A021984 Expansion of 1/((1-x)(1-4x)(1-10x)(1-11x)).

1, 26, 457, 6822, 93333, 1210938, 15168529, 185357774, 2224062445, 26316305730, 307996949481, 3573147901206, 41156463852037, 471239561238602, 5368820120200513, 60908872219620318, 688516109116593309

Offset

0,2

Links

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

Index entries for linear recurrences with constant coefficients, signature (26,-219,634,-440).

Formula

a(n)=(27*11^(n+3) - 35*10^(n+3) + 15*4^(n+3) - 7)/1890. [Yahia Kahloune, Jun 29 2013]

a(0)=1, a(1)=26, a(2)=457, a(3)=6822; for n>3, a(n) = 26*a(n-1) -219*a(n-2) +634*a(n-3) -440*a(n-4). - Vincenzo Librandi, Jul 12 2013

Mathematica

CoefficientList[Series[1 / ((1 - x) (1 - 4 x) (1 - 10 x) (1 - 11 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 12 2013 *)
LinearRecurrence[{26, -219, 634, -440}, {1, 26, 457, 6822}, 20] (* Harvey P. Dale, Jun 29 2018 *)

Prog

(Magma) I:=[1, 26, 457, 6822]; [n le 4 select I[n] else 26*Self(n-1)-219*Self(n-2)+634*Self(n-3)-440*Self(n-4): n in [1..25]]; /* or */ m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-4*x)*(1-10*x)*(1-11*x)))); // Vincenzo Librandi, Jul 12 2013

Crossrefs

Sequence in context: A025955 A022725 A020606 * A025954 A158436 A158431

Adjacent sequences: A021981 A021982 A021983 * A021985 A021986 A021987

Keyword

nonn,easy

Author

N. J. A. Sloane.

Status

approved