A025942 Expansion of 1/((1-2x)(1-3x)(1-6x)(1-12x)).

1, 23, 361, 4907, 62545, 773171, 9415897, 113824139, 1370909089, 16481083619, 197954225833, 2376538571771, 28524991618033, 342339076723667, 4108303998843769, 49301058498065003, 591621165177427777

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (23, -168, 468, -432).

Programs

Mathematica

CoefficientList[Series[1/((1-2x)(1-3x)(1-6x)(1-12x)),{x,0,30}],x] (* or *) LinearRecurrence[{23,-168,468,-432},{1,23,361,4907},20] (* Harvey P. Dale, Oct 20 2012 *)

PARI

Vec(1/((1-2*x)*(1-3*x)*(1-6*x)*(1-12*x))+O(x^99)) \\ Charles R Greathouse IV, Sep 26 2012

Formula

a(0)=1, a(1)=23, a(2)=361, a(3)=4907, a(n)=23*a(n-1)-168*a(n-2)+ 468*a(n-3)- 432*a(n-4). - Harvey P. Dale, Oct 20 2012

a(n) = 16*12^n/5 -3*6^n -2^n/5 +3^n. - R. J. Mathar, Jun 04 2013