A025984 Expansion of 1/((1-2*x)*(1-4*x)*(1-10*x)*(1-12*x)).

1, 28, 524, 8288, 119952, 1646400, 21834688, 282827776, 3602179328, 45309135872, 564541565952, 6982826532864, 85877229359104, 1051359996166144, 12824652929417216, 155979167054692352, 1892583332263034880, 22919333297583292416, 277115332812706938880

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..900

Index entries for linear recurrences with constant coefficients, signature (28,-260,896,-960).

Formula

a(n) = -2^n/20+2*4^n/3-125*10^n/12+54*12^n/5. - R. J. Mathar, Jun 20 2013

a(n) = (4^(n+1)-2^(n+1))/2+22*a(n-1)-120*a(n-2). - Vincenzo Librandi, Jul 03 2026

Mathematica

CoefficientList[Series[1/((1-2x)(1-4x)(1-10x)(1-12x)), {x, 0, 20}], x] (* Harvey P. Dale, Apr 03 2017 *)
(* Alternative: *)
LinearRecurrence[{28, -260, 896, -960}, {1, 28, 524, 8288}, 20] (* Harvey P. Dale, Apr 03 2017 *)

Prog

(Magma) I:=[1, 28]; [n le 2 select I[n] else (4^n-2^n)/2+22*Self(n-1)-120*Self(n-2): n in [1..19]]; // Vincenzo Librandi, Jul 03 2026

Crossrefs

Sequence in context: A024434 A024440 A024347 * A020977 A020973 A023947

Adjacent sequences: A025981 A025982 A025983 * A025985 A025986 A025987

Keyword

nonn,easy

Author

N. J. A. Sloane

Extensions

More terms from Vincenzo Librandi, Jul 03 2026

Status

approved