A028116 Expansion of 1 / ((1-4*x)*(1-5*x)*(1-7*x)*(1-9*x)).

1, 25, 398, 5162, 59619, 640227, 6549376, 64780804, 625573157, 5936696909, 55620675474, 516146265726, 4755391291015, 43574880995671, 397637888433092, 3617137005125528, 32823750870307593, 297304128579802113, 2688988551055876630, 24293750984286505810

Offset

0,2

Links

Colin Barker, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (25,-227,887,-1260).

Formula

a(n) = (3*9^(n+3) - 10*7^(n+3) + 3*5^(n+4) - 2*4^(n+4))/120. -Yahia Kahloune, Jun 11 2013

a(n) = 25*a(n-1) - 227*a(n-2) + 887*a(n-3) - 1260*a(n-4) for n>3. - Colin Barker, Apr 17 2017

Mathematica

CoefficientList[Series[1/((1-4x)(1-5x)(1-7x)(1-9x)), {x, 0, 30}], x] (* or *) LinearRecurrence[{25, -227, 887, -1260}, {1, 25, 398, 5162}, 30] (* Harvey P. Dale, Apr 18 2018 *)

Prog

(PARI) Vec(1 / ((1 - 4*x)*(1 - 5*x)*(1 - 7*x)*(1 - 9*x)) + O(x^30)) \\ Colin Barker, Apr 17 2017

Crossrefs

Sequence in context: A028130 A286719 A174515 * A028075 A042204 A028112

Adjacent sequences: A028113 A028114 A028115 * A028117 A028118 A028119

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved