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.

A121414 Column 2 of triangle A121412, in which row n of T=A121412 equals row (n-1) of T^(n+1) with an appended '1'.

Original entry on oeis.org

1, 1, 5, 45, 581, 9730, 199692, 4843125, 135345925, 4278317373, 150818840250, 5863215069621, 249105031449435, 11480173020040450, 570303168053225908, 30375972794764190385, 1726700205634807475115, 104332294453480284687895
Offset: 0

Views

Author

Paul D. Hanna, Aug 22 2006

Keywords

Comments

Also equals column 4 of triangle A101479.

Crossrefs

Cf. A121412 (triangle); other columns: A101483, A121413, A121415; A101479 (triangle).

Programs

  • PARI
    {a(n)=local(A=Mat(1), B); for(m=1, n+3, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i, B[i, j]=1, B[i, j]=(A^i)[i-1, j]); )); A=B); return((A^1)[n+3, 3])}