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.

A103353 First column of triangular matrix A103244.

Original entry on oeis.org

1, 2, 20, 512, 25392, 2093472, 260555392, 45819233280, 10849051434240, 3334632688448000, 1292876470540099584, 617862114722159788032, 357118557050589336432640, 245715466325821945360588800, 198568949299946066906578944000, 186309450278791634742517692366848
Offset: 1

Views

Author

Paul D. Hanna, Feb 02 2005

Keywords

Crossrefs

Cf. A103244.

Programs

  • Mathematica
    nmax = 16;
    P = Table[If[n >= k, (-k^2-k)^(n-k)/(n-k)!, 0], {n, 1, nmax}, {k, 1, nmax}] // Inverse;
    T[n_, k_] := If[n < k || k < 1, 0, P[[n, k]] (n - k)!];
    a[n_] := T[n, 1];
    Array[a, nmax] (* Jean-François Alcover, Aug 09 2018, from PARI *)
  • PARI
    {a(n)=local(P);if(n>=1, P=matrix(n,n,r,c,if(r>=c,(-c^2-c)^(r-c)/(r-c)!))); return(if(n<1,0,(P^-1)[n,1]*(n-1)!))}

Formula

For n>1: 0 = Sum_{k=1..n} C(n-1, k-1)*(-k^2-k)^(n-k)*a(k).