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.

A143080 Triangular sequence of coefficients from an exponential based polynomial: p(x,n)=If[n == 0, 1, -(2*n - 1)!*x^(2*n)*(Sum[x^i/(i + 2*n)!, {i, 0, Infinity}] - Exp[x]/x^(2*n))].

Original entry on oeis.org

1, 1, 1, 6, 6, 3, 1, 120, 120, 60, 20, 5, 1, 5040, 5040, 2520, 840, 210, 42, 7, 1, 362880, 362880, 181440, 60480, 15120, 3024, 504, 72, 9, 1, 39916800, 39916800, 19958400, 6652800, 1663200, 332640, 55440, 7920, 990, 110, 11, 1, 6227020800, 6227020800
Offset: 1

Views

Author

Roger L. Bagula and Gary W. Adamson, Oct 15 2008

Keywords

Comments

Row sums are: 1, 2, 16, 326, 13700, 986410, 108505112, ...
These polynomials are based on: f(x)=1/(1-x)-exp(x).
The n-th row is the coefficient list of the permanental polynomial of the (2n-1)X(2n-1) matrix consisting entirely of 1's (see latter Mathematica code below). - John M. Campbell, Jul 05 2012

Examples

			{1},
{1, 1},
{6, 6, 3, 1},
{120, 120, 60, 20, 5, 1},
{5040, 5040, 2520, 840, 210, 42, 7, 1},
{362880, 362880, 181440, 60480, 15120, 3024, 504, 72, 9, 1},
{39916800, 39916800, 19958400, 6652800, 1663200, 332640, 55440, 7920, 990, 110, 11, 1},
{6227020800, 6227020800, 3113510400, 1037836800, 259459200, 51891840, 8648640, 1235520, 154440, 17160, 1716, 156, 13, 1}
		

Crossrefs

Programs

  • Mathematica
    Clear[f, x, n, a]; f[x_, n_] := f[x, n] = If[n == 0, 1, -(2*n - 1)!*x^(2*n)*(Sum[x^i/(i + 2*n)!, {i, 0, Infinity}] - Exp[x]/x^(2*n))]; a = Table[CoefficientList[FullSimplify[f[x, n]], x], {n, 0, 10}]; Flatten[a]
    Permanent[m_List] := With[{v = Array[x, Length[m]]}, Coefficient[Times @@ (m.v), Times @@ v]]; A[q_] := Array[1 &, {q, q}]; Flatten[Table[Abs[CoefficientList[Expand[Permanent[A[2*n-1] - IdentityMatrix[2*n-1]*x]], x]], {n, 6}]] (* John M. Campbell, Jul 05 2012 *)

Formula

p(x,n)=If[n == 0, 1, -(2*n - 1)!*x^(2*n)*(Sum[x^i/(i + 2*n)!, {i, 0, Infinity}] - Exp[x]/x^(2*n))]; t(n,m)=Coefficients(p)x,n)).