A077821 Expansion of (1-x)^(-1)/(1-3*x-3*x^2-3*x^3).

1, 4, 16, 64, 253, 1000, 3952, 15616, 61705, 243820, 963424, 3806848, 15042277, 59437648, 234860320, 928020736, 3666956113, 14489511508, 57253465072, 226229798080, 893918323981, 3532204761400, 13957058650384, 55149545207296, 217916425857241, 861069089144764

Offset

0,2

Links

Table of n, a(n) for n=0..25.

Index entries for linear recurrences with constant coefficients, signature (4, 0, 0, -3).

Formula

a(0)=1, a(1)=4, a(2)=16, a(3)=64, a(n)=4*a(n-1)-3*a(n-4) [From Harvey P. Dale, May 10 2011]

Mathematica

LinearRecurrence[{4, 0, 0, -3}, {1, 4, 16, 64}, 40] (* or *) CoefficientList[ Series[(1-x)^(-1)/(1-3x-3x^2-3x^3), {x, 0, 40}], x] (* Harvey P. Dale, May 10 2011 *)

Crossrefs

Sequence in context: A188714 A005755 A269651 * A215877 A206450 A294452

Adjacent sequences: A077818 A077819 A077820 * A077822 A077823 A077824

Keyword

nonn

Author

N. J. A. Sloane, Nov 17 2002

Status

approved