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.

A154646 Triangle T(n,k) with the coefficient [x^k] of the series (1-x)^(n+1)* sum_{m=0..infinity} [(3*m+1)^n + (3*m+2)^n]*x^m in row n, column k.

Original entry on oeis.org

2, 3, 3, 5, 26, 5, 9, 153, 153, 9, 17, 796, 2262, 796, 17, 33, 3951, 25176, 25176, 3951, 33, 65, 19266, 243111, 524876, 243111, 19266, 65, 129, 93477, 2168235, 8760639, 8760639, 2168235, 93477, 129, 257, 453848, 18445820, 127880936, 235517318
Offset: 0

Views

Author

Roger L. Bagula, Jan 13 2009

Keywords

Comments

Row sums are 2, 6, 36, 324, 3888, 58320, 1049760, 22044960, 529079040, 14285134080,
428554022400,...

Examples

			2;
3, 3;
5, 26, 5;
9, 153, 153, 9;
17, 796, 2262, 796, 17;
33, 3951, 25176, 25176, 3951, 33;
65, 19266, 243111, 524876, 243111, 19266, 65;
129, 93477, 2168235, 8760639, 8760639, 2168235, 93477, 129;
257, 453848, 18445820, 127880936, 235517318, 127880936, 18445820, 453848, 257;
		

Programs

  • Maple
    A154646 := proc(n,k)
        (-1)^(n+1)*(x-1)^(n+1)*add(x^j*((3*j+1)^n+(3*j+2)^n),j=0..k) ;
        coeftayl(%,x=0,k) ;
    end proc: # R. J. Mathar, Jul 23 2012
  • Mathematica
    Clear[p]; p[x_, n_] = (-1)^(n + 1)*(x - 1)^(n + 1)*Sum[(3*m + 2)^n*x^m, {m, 0, Infinity}]
    + (-1)^(n + 1)*(x - 1)^(n + 1)*Sum[(3*m + 1)^n*x^m, {m, 0, Infinity}];
    Table[FullSimplify[ExpandAll[p[x, n]]], {n, 0, 10}];
    Table[CoefficientList[FullSimplify[ExpandAll[p[x, n]]], x], {n, 0, 10}];
    Flatten[%]
    Contribution from Roger L. Bagula, Nov 27 2009: (Start)
    p[t_] = Exp[t]*x/((-Exp[3*t] + x)) + Exp[2*t]*x/((-Exp[3*t] + x));
    a = Table[ CoefficientList[FullSimplify[ExpandAll[(n!*(-1 + x)^(n + 1)/x)*SeriesCoefficient[ Series[p[t], {t, 0, 30}], n]]], x], {n, 0, 10}];
    Flatten[a] (End)