Charlie, (2(n+1)^3-(n+1)^2+5n^2-1)*2^n/16 (equivalently,(n^3+5n^2+2n)*2^n/8) solves for all n in your list.
Does this count as 'proof'?
Edited on April 29, 2011, 7:25 am
blackjack
flooble's webmaster puzzle