A113436 First row of A113435.

1, 2, 7, 26, 98, 371, 1406, 5329, 20196, 76532, 289997, 1098826, 4163483, 15775426, 59772826, 226477879, 858118966, 3251390237, 12319431012, 46677994276, 176861668393, 670124115506, 2539082288671, 9620514646154, 36451871795186

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (7,-15,11,-1).

Formula

a(n) = A113435(3*n).

a(n) = 7*a(n-1) - 15*a(n-2) + 11*a(n-3) - a(n-4).

G.f.: (1 -5*x +8*x^2 -4*x^3)/(1 -7*x +15*x^2 -11*x^3 +x^4).

Mathematica

CoefficientList[Series[(1 - 5*x + 8*x^2 - 4*x^3)/(1 - 7*x + 15*x^2 - 11*x^3 + x^4), {x, 0, 50}], x] (* or *) LinearRecurrence[{7, -15, 11, -1}, {1, 2, 7, 26}, 50] (* G. C. Greubel, Mar 10 2017 *)

Prog

(PARI) my(x='x+ O(x^50)); Vec((1 -5*x +8*x^2 -4*x^3)/(1 -7*x +15*x^2 -11*x^3 +x^4)) \\ G. C. Greubel, Mar 10 2017

Crossrefs

Cf. A113435.

Sequence in context: A278351 A001075 A293210 * A126223 A369231 A369489

Adjacent sequences: A113433 A113434 A113435 * A113437 A113438 A113439

Keyword

nonn

Author

Floor van Lamoen, Nov 04 2005

Status

approved