cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A021844 Expansion of 1/((1-x)*(1-4*x)*(1-6*x)*(1-12*x)).

Original entry on oeis.org

1, 23, 363, 4963, 63539, 787731, 9609811, 116281811, 1401253587, 16850623699, 202422366419, 2430363281619, 29172151056595, 350112652220627, 4201633221810387, 50421288464357587, 605065606114711763, 7260848163537557715, 87130543395042760915, 1045568713702569416915
Offset: 0

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Programs

  • Mathematica
    CoefficientList[Series[1/((1-x)(1-4x)(1-6x)(1-12x)),{x,0,40}],x] (* or *) LinearRecurrence[{23,-166,432,-288},{1,23,363,4963},40] (* Harvey P. Dale, May 11 2011 *)
  • PARI
    Vec(1/((1-x)*(1-4*x)*(1-6*x)*(1-12*x))+O(x^99)) \\ Charles R Greathouse IV, Sep 26 2012

Formula

a(n) = 3*12^(n+1)/11 -3*6^(n+1)/5 +2^(2*n+2)/3 -1/165. - R. J. Mathar, Mar 15 2011
a(0)=1, a(1)=23, a(2)=363, a(3)=4963, a(n) = 23*a(n-1)-166*a(n-2)+432*a(n-3)-288*a(n-4). - Harvey P. Dale, May 11 2011