# Friday Poser



## SteveO59L (Apr 24, 2009)

What is the next number in this series ?

1, 2, 6, 42, 1806,?

No prizes, just lots of kudos for the first correct answer


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## Domski (Apr 24, 2009)

3265248???

Dom


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## SteveO59L (Apr 24, 2009)

Close, but no cigar. My friend


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## Domski (Apr 24, 2009)

SteveO59L said:


> Close, but no cigar. My friend


 
I guessed so, number series have always been like crosswords and anagrams to me i.e. incomprehensible.

Dom


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## Domski (Apr 24, 2009)

Actually I think I was close: 3263442???

Dom


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## LouieP (Apr 24, 2009)

How about 3263442


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## SteveO59L (Apr 24, 2009)

Correct


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## Domski (Apr 24, 2009)

SteveO59L said:


> Correct


 
Are you sure there's no prize?


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## schielrn (Apr 24, 2009)

Domski said:


> Are you sure there's no prize?


The satisfaction that it only took you 2 guesses.


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## Domski (Apr 24, 2009)

schielrn said:


> The satisfaction that it only took you 2 guesses.


 
Educated guesses if you don't mind  

The first one was more a whack with a hammer than anything else although it got me thinking along the right lines.


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## Jon von der Heyden (Apr 24, 2009)

And the solution:

Excel WorkbookABCDE11264218062264218063263442Index


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## LouieP (Apr 24, 2009)

Quite simply:

a=a(n-1)^2+a(n-1) 
where a(0)=1


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## Domski (Apr 24, 2009)

LouieP said:


> Quite simply:
> 
> a=a(n-1)^2+a(n-1)
> where a(0)=1


 
I was just going to say that


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## al_b_cnu (Apr 24, 2009)

ok,

Next one: What are the Euro Lotto numbers going to be tonight then?


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## al_b_cnu (Apr 24, 2009)

Oh yes, correct answers by PM only please


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## Domski (Apr 24, 2009)

I'm not even going to think about that one because then I'd have to go and buy a ticket, and then I woudn't be able to stop buying them in case my numbers came up. They got me that way with the original lottery!!!


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## al_b_cnu (Apr 24, 2009)

I just do (un)lucky dips when there's a roll over


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## Cbrine (Apr 24, 2009)

The winning numbers for the Euro Lotto will be:

2 28 45 46 47 7 3

I would suggest the you remove your entire life savings and purchase tickets with it


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## al_b_cnu (Apr 24, 2009)

I'm delving into my post office account now!

Will £1.49 cover it?


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## Oorang (Apr 25, 2009)

post another


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## Scott Huish (Apr 26, 2009)

The solution to the original problem is:

=A1*(A1+1)

because your basically just multiplying the number * (number + 1) to get the next number in the sequence


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## Oorang (Apr 26, 2009)

10,4,24,32,80,144,272,528, ..?


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## Oorang (Apr 26, 2009)

Totally unrelated side note... I can't even look at HotPepper's avatar without bursting out into a terrible rendition of "Free Falling".


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## Stormseed (Apr 27, 2009)

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BORDER-BOTTOM: #d4d0c8 0.5pt solid; FONT-FAMILY: Arial; BACKGROUND-COLOR: #ffffff; TEXT-ALIGN: right"> </TD></TR><TR><TD style="BORDER-TOP: #000000 0.5pt solid; FONT-SIZE: 10pt; BORDER-LEFT: #000000 0.5pt solid; COLOR: #000000; FONT-FAMILY: menu; BACKGROUND-COLOR: #d4d0c8" align=middle width="2%"><CENTER>4</CENTER></TD><TD style="BORDER-RIGHT: #d4d0c8 0.5pt solid; FONT-SIZE: 9pt; VERTICAL-ALIGN: bottom; BORDER-LEFT: #000000 0.5pt solid; COLOR: #000000; BORDER-BOTTOM: #d4d0c8 0.5pt solid; FONT-FAMILY: Arial; BACKGROUND-COLOR: #ffffff; TEXT-ALIGN: right">1806</TD><TD style="BORDER-RIGHT: #d4d0c8 0.5pt solid; FONT-SIZE: 9pt; VERTICAL-ALIGN: bottom; COLOR: #000000; BORDER-BOTTOM: #d4d0c8 0.5pt solid; FONT-FAMILY: Arial; BACKGROUND-COLOR: #ffffff; TEXT-ALIGN: right"> </TD><TD style="BORDER-RIGHT: #d4d0c8 0.5pt solid; FONT-SIZE: 9pt; VERTICAL-ALIGN: bottom; COLOR: #000000; BORDER-BOTTOM: #d4d0c8 0.5pt solid; FONT-FAMILY: Arial; BACKGROUND-COLOR: #ffffff; TEXT-ALIGN: right"> </TD><TD style="BORDER-RIGHT: #000000 0.5pt solid; FONT-SIZE: 9pt; VERTICAL-ALIGN: bottom; COLOR: #000000; BORDER-BOTTOM: #d4d0c8 0.5pt solid; FONT-FAMILY: Arial; BACKGROUND-COLOR: #ffffff; TEXT-ALIGN: right"> </TD></TR><TR><TD style="BORDER-TOP: #000000 0.5pt solid; FONT-SIZE: 10pt; BORDER-LEFT: #000000 0.5pt solid; COLOR: #000000; FONT-FAMILY: menu; BACKGROUND-COLOR: #d4d0c8" align=middle width="2%"><CENTER>5</CENTER></TD><TD style="BORDER-RIGHT: #d4d0c8 0.5pt solid; FONT-SIZE: 9pt; VERTICAL-ALIGN: bottom; BORDER-LEFT: #000000 0.5pt solid; COLOR: #000000; BORDER-BOTTOM: #d4d0c8 0.5pt solid; FONT-FAMILY: Arial; BACKGROUND-COLOR: #ffffff; TEXT-ALIGN: right">3263442</TD><TD style="BORDER-RIGHT: #d4d0c8 0.5pt solid; FONT-SIZE: 9pt; VERTICAL-ALIGN: bottom; COLOR: #000000; BORDER-BOTTOM: #d4d0c8 0.5pt solid; FONT-FAMILY: Arial; BACKGROUND-COLOR: #ffffff; TEXT-ALIGN: right"> </TD><TD style="BORDER-RIGHT: #d4d0c8 0.5pt solid; FONT-SIZE: 9pt; VERTICAL-ALIGN: bottom; COLOR: #000000; BORDER-BOTTOM: #d4d0c8 0.5pt solid; FONT-FAMILY: Arial; BACKGROUND-COLOR: #ffffff; TEXT-ALIGN: right"> </TD><TD style="BORDER-RIGHT: #000000 0.5pt solid; FONT-SIZE: 9pt; VERTICAL-ALIGN: bottom; COLOR: #000000; BORDER-BOTTOM: #d4d0c8 0.5pt solid; FONT-FAMILY: Arial; BACKGROUND-COLOR: #ffffff; TEXT-ALIGN: right"> </TD></TR><TR><TD style="BORDER-RIGHT: #000000 0.5pt solid; BORDER-TOP: #808080 0.5pt solid; BORDER-LEFT: #000000 0.5pt solid; BORDER-BOTTOM: #000000 0.5pt solid; BACKGROUND-COLOR: #d4d0c8" colSpan=5><TABLE width="100%" align=left VALIGN="TOP"><TBODY><TR><TD style="BORDER-RIGHT: #000000 0.5pt solid; BORDER-TOP: #808080 0.5pt solid; BORDER-LEFT: #000000 0.5pt solid; WIDTH: 120pt; BORDER-BOTTOM: #000000 0.5pt solid; BACKGROUND-COLOR: #ffffff" align=left>Sheet1</TD><TD> </TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE>
[HtmlMaker 2.42] To see the formula in the cells just click on the cells hyperlink or click the Name box
PLEASE DO NOT QUOTE THIS TABLE IMAGE ON SAME PAGE! OTHEWISE, ERROR OF JavaScript OCCUR.</CENTER> 
=1*(1+1)
=2*(2+1)
=6*(6+1)
=42*(42+1)
=1806*(1806+1)


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## Jon von der Heyden (Apr 27, 2009)

Bit of a guess but 992 perhaps?


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## Oorang (Apr 27, 2009)

No, but I'm curious what yielded 992?

Note: Upon reflection this may not be a fair sequence, so I will leave it until noon then post the answer.


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## schielrn (Apr 27, 2009)

I would think it would be 1072, but on recalculating it seems that I don't match your 272 and beyond?

So after I recalculate those numbers I get 1200, but not sure if it is the same patterns were judging?

But my pattern is all dependent upon the first number and 2nd number.


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## barry houdini (Apr 27, 2009)

looks like it should be 1040 or 1072 but I can't decide which it should be......


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## LouieP (Apr 27, 2009)

barry houdini said:


> looks like it should be 1040 or 1072 but I can't decide which it should be......


 

I'd agree with 1040


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## yytsunamiyy (Apr 27, 2009)

1072 as a guess (n= 2n-2 + n-1)


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## Oorang (Apr 27, 2009)

1040 is the correct answer Care to post your formula?


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## Jon von der Heyden (Apr 27, 2009)

Oorang said:


> No, but I'm curious what yielded 992?
> 
> Note: Upon reflection this may not be a fair sequence, so I will leave it until noon then post the answer.


 
Er, I can't seem to replicate it.  I confess that I never made it far enough in school to cover this sort of subject.


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## Oorang (Apr 27, 2009)

Solution: (A1 Xor A2) + A1... copy down.

I was trying to see if there was a mathematic way to replicate Xor, but the formula got ridiculous and that was when I was like "hmmm that may not have been fair". (BTW extra points for anyone who knows a simple way to do that with math operators)


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## Scott Huish (Apr 27, 2009)

An Excel way could be:

=(OR(A1=7,A2=9)<>AND(A1=7,A2=9))


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## barry houdini (Apr 27, 2009)

For XOR perhaps

=(A1=7)+(A2=9)=1

....as for 1040 I still don't see why it should be the next in the series. My answer (1040 or 1072) was based on the logic being

n+1 = (n+/-8)*2

but I couldn't work out when it was +8 and when it was -8......


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## Oorang (Apr 27, 2009)

barry houdini said:


> ....as for 1040 I still don't see why it should be the next in the series.


 
Theoretically, any formula that replicates the number sequence given would be "right". The Xor formula is just right_er_ by virtue of being the one I used


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## Scott Huish (Apr 28, 2009)

OK, what's the next number in the sequence?

1, 7, 25, 61, 121, 211, ?


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## barry houdini (Apr 28, 2009)

337


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## Scott Huish (Apr 28, 2009)

Yep, very good.


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## Oorang (Apr 28, 2009)

Yah, but that one was google-able


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## Scott Huish (Apr 28, 2009)

OK, let's see if this is more difficult:

1, 92, 175, 254, 331,?


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## Oaktree (Apr 28, 2009)

I think it's 407.  The next 3 would then be 482.5, 557.75, and 632.875


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## Scott Huish (Apr 28, 2009)

Close, but no.

I will say this, there are no fractional amounts in the answers.


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## DreamAlchemist (Apr 28, 2009)

412, 655 are the next 2 in the series.

(THough my first method got me the same numbers as Oaktree.


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## DreamAlchemist (Apr 28, 2009)

Couldnt edit my prior post I revisited the first method and got this series close to the original thought.

407, 483, 560, 639


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## Scott Huish (Apr 28, 2009)

Nope.


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## dave3009 (Apr 28, 2009)

Has it to do with the number 8, seems that if you disclude the last digit the numbers run in 8's 1, 9, 17, 25, 33.  Now just what drives that last digit?


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## Scott Huish (Apr 28, 2009)

It has nothing to do with the number 8.


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## Scott Huish (Apr 29, 2009)

The hint so far: there are no fractional amounts in the answers.

Here's another:

The square root of 1 is 1.


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## Andrew Fergus (Apr 29, 2009)

Is 406 the next number?


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## Jonmo1 (Apr 29, 2009)

407


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## schielrn (Apr 29, 2009)

I too came to 407 with my first attempt, but then I am coming to 426, but it is not building off the previous number, so I am not correct, but there is a nice little formula I concocted to get that, but it did not provide the right answer for 331, so I am still off base here.


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## SteveO59L (Apr 29, 2009)

I get 407, but that reduces the index to 1. So I cant get any higher.


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## LouieP (Apr 29, 2009)

what about 411 ?


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## Jonmo1 (Apr 29, 2009)

The question does not ask to go any higher, it only asks for the next number.


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## SteveO59L (Apr 29, 2009)

Well spotted


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## Scott Huish (Apr 29, 2009)

No, the next number has not been given yet. There are numbers higher in the sequence than just the missing one I asked for.


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## DreamAlchemist (Apr 29, 2009)

Ok I found that by utilizeing the average of 2 numbers (a&b) and then the decreasing amount of the average (average of a&b minus the average of b&c) I got the answer of 410 for the next answer.


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## Scott Huish (Apr 29, 2009)

Nope.


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## Scott Huish (Apr 29, 2009)

OK, the first number is 1.
The square root of 1 is 1.
How can you utilize this to get the 2nd number, and then the rest?
There are no fractions in the answers, so fractional amounts are being ignored somewhere.


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## Andrew Fergus (Apr 29, 2009)

How about 405 followed by 477, 548, 617, 685 & 751?

Andrew


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## Scott Huish (Apr 29, 2009)

You got it!


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## Andrew Fergus (Apr 29, 2009)

***SPOILER ALERT***



This was the formula I used:
A2 =A1+92-INT(SQRT(A1))


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## Scott Huish (Apr 29, 2009)

Yep, that's it exactly.


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## Andrew Fergus (Apr 29, 2009)

Given a starting number of 1, what is/are the next number/s in the following sequence:

1, 3, 15, 46, 92, 107, 164, 191


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## Isabella (Apr 30, 2009)

Andrew Fergus said:


> ***SPOILER ALERT***
> 
> 
> 
> ...


 
How would you do this on paper, i dont understand the "INT" part


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## Jonmo1 (Apr 30, 2009)

INT is the whole number (left of decimal point) of a number...

12.24 INT = 12
35.7676 INT = 35
6.0000 INT = 6

SQRT of coarse = Square Root


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## Scott Huish (Apr 30, 2009)

On paper you would just drop the fractional part.



> INT is the whole number (left of decimal point) of a number...


when dealing with positive numbers. 

INT in Excel actually rounds down to the nearest integer.


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## Jonmo1 (Apr 30, 2009)

I saw that, that's why I didn't give any negative number examples. I figured negative numbers didn't apply to this excercise, so...


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## Andrew Fergus (Apr 30, 2009)

Andrew Fergus said:


> Given a starting number of 1, what is/are the next number/s in the following sequence:
> 
> 1, 3, 15, 46, 92, 107, 164, 191


No takers?

Despite the apparent randomness, it is simpler than it looks.  It may actually be easier to break this using a pen and paper rather than Excel.

Some hints:
Each number (other than the first) is calculated using X + Y + Z, where:
X = the previous number
Y = a function based on the previous number (not a standard Excel 'function' per se but a mathematical function nonetheless)
Z = a function based on the previous number mod 10 i.e. F(mod(n,10)) not mod(F,10)

Andrew


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## barry houdini (May 1, 2009)

So the next 3 are

203, 217, 276

How about this series?

15, 14, 4, 10, 6, 13, ?


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## LouieP (May 1, 2009)

barry houdini said:


> how about this series?
> 
> 15, 14, 4, 10, 6, 13, ?


 

1, 13, 10, 10


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## barry houdini (May 1, 2009)

Nice one Louie! Was that too easy, what about this?

13, 22, 5, 13, 10, 19, ?


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## LouieP (May 1, 2009)

barry houdini said:


> Nice one Louie! Was that too easy, what about this?
> 
> 13, 22, 5, 13, 10, 19, ?


 

21, 14. You like your planets then eh?


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## LouieP (May 1, 2009)

What are the next 2 numbers?

1, 3, 10, _, 126, 462,


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## Andrew Fergus (May 1, 2009)

barry houdini said:


> So the next 3 are
> 
> 203, 217, 276


Correct.

Do you want to share your formula/method?

Andrew


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## barry houdini (May 1, 2009)

I think your hints gave a little too much information, Andrew 

I believe each number is the sum of the previous number plus the sum of the digits of the previous number plus the square of the last digit of the previous number.

Not particularly easy to do with an excel formula but if you put 1 in A1 and this formula in A2 

=A1+MOD(A1,10)^2+SUMPRODUCT(MID(A1,ROW(INDIRECT("1:"&LEN(A1))),1)+0)

dragged down that'll reproduce the series


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## Andrew Fergus (May 1, 2009)

barry houdini said:


> I think your hints gave a little too much information, Andrew


I know - given there were no takers I thought maybe it was too hard! 

Your method is exactly right.  Interesting use of sumproduct and indirect to get the sum of the digits.  I used the following array formula:
=SUM(G1, MOD(A1,10)^2, IF(LEN(A1)>=ROW(A$1:A2), 0+(MID(A1, ROW(A$1:A2), 1)),0))

Andrew


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## dave3009 (May 1, 2009)

Right seeing as how there are minute left of friday I'm going away with a caravan tomorrow

30, 

What should be the next number


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## Scott Huish (May 4, 2009)

Hard to find a pattern with only 1 number, so I am guessing 0.


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## Scott Huish (May 4, 2009)

What's the next number?

2, 9, 16, 23, 30, 6, ?


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## Jonmo1 (May 4, 2009)

Is it?

2, 9, 16, 23, 30, 6, 13, 20, 27, 34, 10, 17, 24, 31, 38


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## Scott Huish (May 4, 2009)

It was correct up until the 27 then it wasn't.


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## Scott Huish (May 4, 2009)

What's the next number?

2, 9, 16, 23, 30, 6, 13, 20, 27, ?


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## Andrew Fergus (May 4, 2009)

3.

I'm guessing A2 = Mod(A1 + 7, 31)


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## barry houdini (May 4, 2009)

6


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## Scott Huish (May 4, 2009)

jonmo had the original correct answer up to the 27 and barry has the next correct number after that


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## barry houdini (May 4, 2009)

I'm assuming it's date-related, Fridays in 2009 for instance, just the day, in which case it would go like this:

2, 9, 16, 23, 30, 6, 13, 20, 27, 6, 13, 20, 27, 3, 10 ......


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## Scott Huish (May 4, 2009)

That is correct!


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## Greg Truby (May 5, 2009)

dave3009 said:


> Right seeing as how there are minute left of friday I'm going away with a caravan tomorrow
> 
> 30,
> 
> What should be the next number


 
1?  [Logic being that you posted on May 1st, 30 was the DAY() of posting date - 1.]


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## Scott Huish (May 5, 2009)

You have 2 US coins totalling 55 cents. One of them is not a nickel. What are the two coins?


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## Jonmo1 (May 5, 2009)

That is so old Mr Pepper...

1 is a 50 Cent Piece (Not a Nickel)
the other is a Nickel


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## LouieP (May 15, 2009)

Came across this sequence recently and took me a while to work it out.
What are the next 2 numbers:

1,3,10,35,126,462
**


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