A028053 Expansion of 1/((1-3x)(1-5x)(1-6x)(1-7x)).

1, 21, 280, 3030, 29071, 258111, 2172430, 17592960, 138433141, 1065579801, 8062670980, 60182175690, 444345657211, 3251891531091, 23627323915930, 170652039023220, 1226510307989281, 8779155519807981, 62625124983987280, 445449774932327550, 3160830238141717351

Offset

0,2

Links

Table of n, a(n) for n=0..20.

Index entries for linear recurrences with constant coefficients, signature (21,-161,531,-630).

Formula

a(n) = (3*7^(n+3)-8*6^(n+3)+6*5^(n+3)-3^(n+3))/24. - Yahia Kahloune, May 27 2013

Mathematica

CoefficientList[Series[1/((1-3x)(1-5x)(1-6x)(1-7x)), {x, 0, 30}], x] (* Harvey P. Dale, May 16 2020 *)

Crossrefs

Sequence in context: A334529 A004324 A243421 * A223996 A323063 A028033

Adjacent sequences: A028050 A028051 A028052 * A028054 A028055 A028056

Keyword

nonn

Author

N. J. A. Sloane.

Status

approved