A028055 Expansion of 1/((1-3x)(1-5x)(1-6x)(1-9x)).

1, 23, 340, 4130, 45031, 459893, 4504690, 42928160, 401635861, 3711270563, 34005047440, 309788905790, 2811170579491, 25442007146033, 229842147512590, 2073840099225020, 18696506927851921, 168462145714550303

Offset

0,2

Links

Table of n, a(n) for n=0..17.

Index entries for linear recurrences with constant coefficients, signature (23,-189,657,-810).

Formula

a(n)=(9^(n+3)-8*6^(n+3)+9*5^(n+3)-2*3^(n+3))/72. [Yahia Kahloune, Jun 07 2013]

a(0)=1, a(1)=23, a(2)=340, a(3)=4130, a(n)=23*a(n-1)-189*a(n-2)+ 657*a(n-3)- 810*a(n-4). - Harvey P. Dale, Jul 01 2015

Mathematica

CoefficientList[Series[1/((1-3x)(1-5x)(1-6x)(1-9x)), {x, 0, 30}], x] (* or *) LinearRecurrence[{23, -189, 657, -810}, {1, 23, 340, 4130}, 30] (* Harvey P. Dale, Jul 01 2015 *)

Prog

(PARI) a(n)=(9^(n+3)-8*6^(n+3)+9*5^(n+3)-2*3^(n+3))/72 \\ Charles R Greathouse IV, Jun 07 2013

Crossrefs

Sequence in context: A163512 A028059 A299710 * A026324 A028039 A002118

Adjacent sequences: A028052 A028053 A028054 * A028056 A028057 A028058

Keyword

nonn,easy

Author

N. J. A. Sloane.

Status

approved