A021324 Expansion of 1/((1-x)(1-2x)(1-10x)(1-12x)).

1, 25, 437, 6629, 93429, 1260021, 16509109, 211998133, 2682866357, 33583284917, 416888307381, 5141548576437, 63087471804085, 770938550533813, 9390151495286453, 114070706832309941, 1382737370876575413

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,-188,404,-240).

Formula

a(n) = (36*12^(n+3) - 55*10^(n+3) + 99*2^(n+3) - 80)/7920. [Yahia Kahloune, Jul 07 2013]

a(0)=1, a(1)=25; for n>1, a(n) = 22*a(n-1) -120*a(n-2) +2^n -1. - Vincenzo Librandi, Jul 09 2013

a(0)=1, a(1)=25, a(2)=437, a(3)=6629; for n>3, a(n) = 25*a(n-1) -188*a(n-2) +404*a(n-3) -240*a(n-4). - Vincenzo Librandi, Jul 09 2013

Mathematica

CoefficientList[Series[1 / ((1 - x) (1 - 2 x) (1 - 10 x) (1 - 12 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 09 2013 *)

Prog

(Magma) m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-2*x)*(1-10*x)*(1-12*x)))); // Vincenzo Librandi, Jul 09 2013
(Magma) I:=[1, 25, 437, 6629]; [n le 4 select I[n] else 25*Self(n-1)-188*Self(n-2)+404*Self(n-3)-240*Self(n-4): n in [1..25]]; // Vincenzo Librandi, Jul 09 2013

Crossrefs

Sequence in context: A019722 A180800 A004346 * A092430 A018207 A362428

Adjacent sequences: A021321 A021322 A021323 * A021325 A021326 A021327

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved