A021704 Expansion of 1/((1-x)(1-3x)(1-9x)(1-12x)).

1, 25, 430, 6370, 87451, 1148875, 14682760, 184262740, 2283789301, 28059228925, 342594651490, 4164091223110, 50445694121551, 609637726848175, 7354257305858620, 88598528944951480, 1066309318875820201, 12823854570531174625, 154139539543147216150, 1851954036790468071850, 22243964501945160341251

Offset

0,2

Links

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

Formula

a(n) = (1024*12^n - 891*9^n + 44*3^n - 1)/176. - Christian Krause, Jun 08 2026

Mathematica

CoefficientList[Series[1/((1-x)(1-3x)(1-9x)(1-12x)), {x, 0, 25}], x]  (* Harvey P. Dale, Feb 24 2011 *)

Crossrefs

Sequence in context: A056090 A020448 A203544 * A019742 A019722 A180800

Adjacent sequences: A021701 A021702 A021703 * A021705 A021706 A021707

Keyword

nonn,easy,changed

Author

N. J. A. Sloane

Status

approved