A152551 a(n) = (2*n+1)^floor((n-1)/2).

1, 1, 1, 7, 9, 121, 169, 3375, 4913, 130321, 194481, 6436343, 9765625, 387420489, 594823321, 27512614111, 42618442977, 2251875390625, 3512479453921, 208728361158759, 327381934393961, 21611482313284249, 34050628916015625

Offset: 0

Author

Paul D. Hanna, Dec 07 2008

Keywords

• nonn

Comments

Compare to row sums of triangle A152550: (2n+1)^(n-1).

Triangle A152550 lists coefficients in a q-analog of the function [LambertW(-2x)/(-2x)]^(1/2).

Links

• G. C. Greubel, Table of n, a(n) for n = 0..642

Crossrefs

Cf. A152550, A152552 (q=2), A152553 (q=3).

Programs

Magma

[(2*n+1)^Floor((n-1)/2): n in [0..50]]; // G. C. Greubel, Nov 16 2017

Mathematica

Table[(2n+1)^Floor[(n-1)/2],{n,0,30}] (* Harvey P. Dale, Nov 21 2011 *)

PARI

a(n)=(2*n+1)^((n-1)\2)

Formula

a(n) = Sum_{k=0..n(n-1)/2} A152550(n,k)*(-1)^k.