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.

A156926 Row sums of the FP2 polynomials of A156925.

Original entry on oeis.org

1, 2, -8, -96, 4608, 1105920, -1592524800, -16052649984000, 1294485694709760000, 939485937792555417600000, -6818413142123250198773760000000, -544338467423010707068824846336000000000, 521477993674340011006196823029396275200000000000
Offset: 0

Views

Author

Johannes W. Meijer, Feb 20 2009

Keywords

Comments

|a(n)| is the 2^n times the determinant of the n X n matrix whose element (i,j) equals i^j. - Michel Lagneau, Feb 08 2021

Crossrefs

Row sums of A156925.

Programs

  • Maple
    a:= proc(n) option remember;
          `if`(n=0, 1, -2*n!*a(n-1)*(-1)^n)
        end:
    seq(a(n), n=0..14);  # Alois P. Heinz, Feb 09 2021
  • PARI
    for(n=0,12,print1((-1)^(n\2)*2^n*matdet(matrix(n,n,i,j,i^j)),", ")) \\ Hugo Pfoertner, Feb 09 2021

Formula

Row sum(n+1) = (-1)^(n)*2*(n+1)!*Row sum(n) with Row sum(n=0) = 1.
Let A(x)=sum(k>=0, |a(k)|*x^k ), then A(x)= G(0)/2, where G(k)= 1 + 1/(1 - 2*x*(k+1)!/(2*x*(k+1)! + 1/G(k+1) )); (continued fraction). - Sergei N. Gladkovskii, Jul 10 2013
Let A(x)=sum(k>=0, |a(k)|*x^k ), then A(x)= G(0)/(4*x)- 1/(2*x), where G(k)= 1 + 1/(1 - 2*x*(2*k)!/(2*x*(2*k)! + 1/(1 + 1/(1 - 2*x*(2*k+1)!/(2*x*(2*k+1)! + 1/G(k+1) ))))); (continued fraction). - Sergei N. Gladkovskii, Jul 10 2013
a(n) = A000079(n) * A000178(n) * A057077(n). - Alois P. Heinz, Feb 09 2021