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.

A137387 Triangular sequence from coefficients of the expansion of p(x,t)=Exp[2*x*t]*t/(1 - t).

Original entry on oeis.org

0, 1, 2, 4, 6, 12, 12, 24, 48, 48, 32, 120, 240, 240, 160, 80, 720, 1440, 1440, 960, 480, 192, 5040, 10080, 10080, 6720, 3360, 1344, 448, 40320, 80640, 80640, 53760, 26880, 10752, 3584, 1024, 362880, 725760, 725760, 483840, 241920, 96768, 32256, 9216
Offset: 1

Views

Author

Roger L. Bagula, Apr 26 2008

Keywords

Comments

Row sums = A066534.

Examples

			{0},
{1},
{2, 4},
{6, 12, 12},
{24, 48, 48, 32},
{120, 240, 240, 160, 80},
{720, 1440, 1440, 960, 480, 192},
{5040, 10080, 10080, 6720, 3360, 1344, 448},
{40320, 80640, 80640, 53760, 26880, 10752, 3584, 1024},
{362880, 725760, 725760, 483840, 241920, 96768, 32256, 9216, 2304},
{3628800, 7257600, 7257600, 4838400, 2419200, 967680, 322560, 92160, 23040,5120}
		

References

  • Terrell Hill, Statistical Mechanics, Dover, 1987, page 417

Crossrefs

Cf. A066534.

Programs

  • Mathematica
    p[t_] = Exp[2*x*t]*t/(1 - t); Table[ ExpandAll[n!*SeriesCoefficient[ Series[p[t], {t, 0, 30}], n]], {n, 0, 10}]; a = Table[n!* CoefficientList[SeriesCoefficient[ Series[p[t], {t, 0, 30}], n], x], {n, 0, 10}]; Flatten[a]

Formula

p(x,t)=Exp[2*x*t]*t/(1 - t)=Sum[P(x,n)*t6n/n!,{n,1,Infinity}]; out_n,m=n!*Coefficients(P(x,n)).