A167478 Expansion of (1-2x+6x^2-x^3)/(1-3x+x^2)^2.

1, 4, 19, 75, 264, 869, 2741, 8396, 25175, 74271, 216336, 623689, 1782889, 5060500, 14277019, 40070259, 111954456, 311555501, 863978525, 2388417116, 6584117471, 18104432199, 49667825184, 135974484625, 371543306449, 1013443026724

Offset

0,2

Comments

Hankel transform of A054109.

Links

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

Index entries for linear recurrences with constant coefficients, signature (6,-11,6,-1).

Formula

G.f.: (1-2*x+6*x^2-x^3)/(1-3*x+x^2)^2.

a(n) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3) - a(n-4). - Wesley Ivan Hurt, Jul 28 2022

Mathematica

LinearRecurrence[{6, -11, 6, -1}, {1, 4, 19, 75}, 100] (* G. C. Greubel, Jun 13 2016 *)
CoefficientList[Series[(1-2x+6x^2-x^3)/(1-3x+x^2)^2, {x, 0, 30}], x] (* Harvey P. Dale, Aug 04 2018 *)

Crossrefs

Cf. A054109.

Sequence in context: A009450 A096978 A186810 * A094734 A094578 A130132

Adjacent sequences: A167475 A167476 A167477 * A167479 A167480 A167481

Keyword

easy,nonn

Author

Paul Barry, Nov 04 2009

Status

approved