A095129 Jac(n)(2Jac(n)-1).

0, 1, 1, 15, 45, 231, 861, 3655, 14365, 58311, 232221, 932295, 3725085, 14913991, 59639581, 238612935, 954386205, 3817763271, 15270790941, 61084037575, 244335101725, 977343902151, 3909371414301, 15637499638215, 62549981775645

Offset

0,4

Comments

mod(a(n),3)=A095130(n)

Links

Table of n, a(n) for n=0..24.

Index entries for linear recurrences with constant coefficients, signature (4,5,-20,-4,16).

Formula

G.f. : x(1-3x+6x^2)/((1-x^2)(1-4x)(1-4x^2)); a(n)=2(4^n+1)/9-4(-2)^n/9-2^n/3+(-1)^n/3.

Mathematica

LinearRecurrence[{4, 5, -20, -4, 16}, {0, 1, 1, 15, 45}, 30] (* Harvey P. Dale, Nov 07 2016 *)

Crossrefs

Cf. A001045.

Sequence in context: A127069 A346853 A241731 * A219813 A068513 A267079

Adjacent sequences: A095126 A095127 A095128 * A095130 A095131 A095132

Keyword

easy,nonn

Author

Paul Barry, May 29 2004

Status

approved