A166231 a(n) = 2^C(n+1,2)*A006012(n).

1, 4, 48, 1280, 69632, 7602176, 1660944384, 725849473024, 634418209226752, 1109011408239984640, 3877275019992826380288, 27111105978154633171828736, 379138479844261543254652092416, 10604214183559196000870296488771584

Offset: 0

Author

Paul Barry, Oct 09 2009

Keywords

• easy
• nonn

Comments

Hankel transform of A166228, A166229.

Links

• G. C. Greubel, Table of n, a(n) for n = 0..70

Crossrefs

Cf. A006012, A166228, A166229, A166232.

Programs

Mathematica

Table[2^(Binomial[n + 1, 2])*Sum[Binomial[n, 2 k]*2^(n - k), {k, 0, Floor[n/2]}], {n, 0, 25}] (* G. C. Greubel, May 07 2016 *)

Formula

a(n) = 2^C(n+1,2)*Sum_{k=0..floor(n/2)} C(n,2k)*2^(n-k).

a(n) = 4^n*A166232(n).