A187340 - OEIS

A187340

Hankel transform of A014301(n+1).

1, 2, 5, 5, -2, -11, -11, 2, 17, 17, -2, -23, -23, 2, 29, 29, -2, -35, -35, 2, 41, 41, -2, -47, -47, 2, 53, 53, -2, -59, -59, 2, 65, 65, -2, -71, -71, 2, 77, 77, -2, -83, -83, 2, 89, 89, -2, -95, -95, 2, 101, 101, -2, -107, -107, 2, 113, 113, -2, -119, -119

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..60.

Index entries for linear recurrences with constant coefficients, signature (2,-3,2,-1).

FORMULA

G.f.: (1+4x^2-x^3)/((1-x+x^2))^2;

a(n) = (1-2n)*cos(Pi*n/3)+(2n+3)*sin(Pi*n/3)/sqrt(3).

MATHEMATICA

LinearRecurrence[{2, -3, 2, -1}, {1, 2, 5, 5}, 70] (* Harvey P. Dale, Nov 24 2017 *)

CROSSREFS