A152556 a(n) = 2*(2*n+2)^floor((n-1)/2).

1, 2, 2, 16, 20, 288, 392, 8192, 11664, 320000, 468512, 15925248, 23762752, 963780608, 1458000000, 68719476736, 105046700288, 5642219814912, 8695584276992, 524288000000000, 813342767698944, 54394721876836352, 84841494965553152, 6232805962420322304

Offset

0,2

Comments

Compare to row sums of triangle A152555: 2*(2n+2)^(n-1).

Triangle A152555 lists coefficients in a q-analog of the function LambertW(-2x)/(-2x).

Links

G. C. Greubel, Table of n, a(n) for n = 0..640

Formula

a(n) = Sum_{k=0..n(n-1)/2} A152555(n,k)*(-1)^k.

Mathematica

Table[2(2n+2)^Floor[(n-1)/2], {n, 0, 30}] (* Harvey P. Dale, Nov 13 2012 *)

Prog

(PARI) a(n)=2*(2*n+2)^((n-1)\2)
(Magma) [2*(2*n+2)^(Floor((n-1)/2)): n in [0..30]]; // G. C. Greubel, Nov 17 2017

Crossrefs

Cf. A152555, A152557(q=2), A152558 (q=3) A152559.

Sequence in context: A222954 A240033 A088139 * A113123 A353912 A303567

Adjacent sequences: A152553 A152554 A152555 * A152557 A152558 A152559

Keyword

nonn

Author

Paul D. Hanna, Dec 07 2008

Status

approved