Friday Poser

[barry houdini]

So the next 3 are

203, 217, 276

How about this series?

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

 

[LouieP]

how about this series?

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

1, 13, 10, 10

 

[barry houdini]

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

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

 

[LouieP]

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

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

21, 14. You like your planets then eh?

 

[LouieP]

What are the next 2 numbers?

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

 

[Andrew Fergus]

So the next 3 are

203, 217, 276

Correct.

Do you want to share your formula/method?

Andrew

 

[barry houdini]

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

 

[Andrew Fergus]

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

 

[dave3009]

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

 

[Scott Huish]

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