User talk:Joshua Giambalvo

Polygonal number pattern sequence

I saw the pattern you mentioned in your bio. I agree, it doesn't seem to be in the OEIS. You should add it! (For new sequences, you can do that here -- this is linked at the bottom of the search page and each sequence entry.) I believe the formula is a(n) = 2n^3 + 3n^2 and that this follows from the polygonal number formula:

$P_{s}(n)={\frac {n^{2}(s-2)-n(s-4)}{2}}$

In any case, welcome to the OEIS! - Charles R Greathouse IV 14:24, 5 August 2016 (UTC)