A023955 Expansion of 1/((1-x)(1-6x)(1-8x)(1-10x)).

1, 25, 413, 5693, 70989, 831693, 9347341, 102052621, 1091175437, 11489041421, 119581270029, 1233774903309, 12644058796045, 128906738896909, 1308890633457677, 13248056512466957, 133757151879680013

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (25,-212,668, -480).

Formula

a(n) = (35*10^(n+3) - 90*8^(n+3) + 63*6^(n+3) -8)/2520. [Yahia Kahloune, Jun 30 2013]

a(0)=1, a(1)=25, a(2)=413, a(3)=5693; for n>3, a(n) = 25*a(n-1) -212*a(n-2) +668*a(n-3) -480*a(n-4). - Vincenzo Librandi, Jul 16 2013

Mathematica

CoefficientList[Series[1 / ((1 - x) (1 - 6 x) (1 - 8 x) (1 - 10 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 16 2013 *)

Prog

(Magma) m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-6*x)*(1-8*x)*(1-10*x)))); /* or */ I:=[1, 25, 413, 5693]; [n le 4 select I[n] else 25*Self(n-1)-212*Self(n-2)+668*Self(n-3)-480*Self(n-4): n in [1..25]]; // Vincenzo Librandi, Jul 16 2013

Crossrefs

Sequence in context: A024437 A028041 A025995 * A025980 A025978 A028037

Adjacent sequences: A023952 A023953 A023954 * A023956 A023957 A023958

Keyword

nonn,easy

Author

N. J. A. Sloane.

Status

approved