A161495 - OEIS

A161495

Expansion of x*(3*x-1)*(x-3)/(1-15*x+32*x^2-15*x^3+x^4).

3, 35, 432, 5405, 67773, 850080, 10663107, 133755235, 1677792528, 21045816925, 263993558397, 3311470367040, 41538271098243, 521045872287395, 6535871471114352, 81984366749625245, 1028391763981932093

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OFFSET

1,1

COMMENTS

Proposed by R. Guy in the seqfan list, Mar 29 2009.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..900

Index entries for linear recurrences with constant coefficients, signature (15,-32,15,-1).

FORMULA

G.f. x*(3*x-1)*(x-3)/(1-15*x+32*x^2-15*x^3+x^4).

a(n) = 15*a(n-1)-32*a(n-2)+15*a(n-3)-a(n-4).

(a(n))^2 = A161159(n)*A004254(n) = A003739(n)/(5*(A001906(n))^2).

MATHEMATICA

Rest[CoefficientList[Series[x(3x-1)(x-3)/(1-15x+32x^2-15x^3+x^4), {x, 0, 30}], x]] (* or *) LinearRecurrence[{15, -32, 15, -1}, {3, 35, 432, 5405}, 30] (* Harvey P. Dale, Nov 03 2011 *)

CROSSREFS

Sequence in context: A221223 A006767 A065929 * A179135 A100033 A259557

Adjacent sequences: A161492 A161493 A161494 * A161496 A161497 A161498

KEYWORD

nonn,easy

AUTHOR

R. J. Mathar, Jun 11 2009

STATUS

approved