Friday Poser

[Andrew Fergus]

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

Andrew

 

[Scott Huish]

You got it!

 

[Andrew Fergus]

***SPOILER ALERT***



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

 

[Scott Huish]

Yep, that's it exactly.

 

[Andrew Fergus]

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

 

[Isabella]

***SPOILER ALERT***



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

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

 

[Jonmo1]

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

 

[Scott Huish]

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.

 

[Jonmo1]

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...

 

[Andrew Fergus]

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