dvjustus

Just curious, since you say this as though this is a common problem, is it a common problem?

Not calculus. Factorials and summation rather.

Hi Matt, I understand what you mean. I'm not familiar with the protocols, but at the outset, I should have at least given: 1. the set of non-negative integers as the domain 2. where the correlation was coming from 3. that only the simplest formula was needed (well, "simple" for someone who forgot a lot of Calculus).

Thanks for the explanations and alternatives, bloodhound. Unfortunately I don't yet understand the symbols you are using. But I appreciate it nonetheless.

I don't know if this would help, but I could show where the correlations are coming from. It has to do with possible arrangements, without repeating arrangements containing the same set of units (e.g., 01 and 10 can't be repeated). If there are 0 units, there are 0 arrangements. If there is 1 unit, 1 arrangement... 2 units: 0 1 0 1 01 --- 3 arrangements 3 units: 0 1 2 0 1 2 01 02 12 012 ---- 7 arrangements and so on...

Hi bloodhound, Not sure what you mean, but the domain is [0,∞), and the pattern doesn't deviate from the given function.

Sorry to bother. I got it... f(x) = 2^x - 1

Trying to come up with a function that fits (0,0) (1,1) (2,3) (3,7) (4,15) (5,31) (6,63)... If not too much trouble, help please. Thanks.