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.

A131490 Appears in Taylor series of powers of generalized Bessel functions.

Original entry on oeis.org

1, 1, 3, 16, 130, 1485, 22645, 444136, 10889676, 326345460, 11736144420, 498798542880, 24732729791484, 1415034219327729, 92523874454996985, 6856434802243346320, 571604206230905727880, 53259509403796625217288, 5513868420471764306104008
Offset: 1

Views

Author

Jonathan Vos Post, Jul 28 2007

Keywords

Comments

Integer sequence given between equations (16) and (17) of Bender et al., p. 4. A recursion is found for coefficients of Taylor series of r-th powers of generalized Bessel functions.
A001263^(-1) * [1, 2, 3, ...] = A103364 * [1, 2, 3, ...] = (1, 1, -1, 3, -16, 130, -1485, 22645, ...); where A001263 = the Narayana triangle. - Gary W. Adamson, Jan 02 2008
Image of n^2 under A001263^(-1), i.e., A001263^(-1) *[0,1,4,9,...] is [0, 1, 1, -3, 16, -130, 1485, -22645, 444136, ...]. - Paul Barry, Jul 13 2009

Crossrefs

Programs

  • Maple
    A131490 := proc(n) local twos,resul; resul := twos*taylor(BesselI(0,twos),twos=0,2*n+3) ; resul := resul/taylor(BesselI(1,twos),twos=0,2*n+3) ; resul := taylor(resul-4,twos=0,2*n+3) ; resul := coeftayl(resul,twos=0,2*n) ; resul := resul*4^n/2 ; abs(resul*factorial(n+1)*factorial(n)) ; end: seq(A131490(n),n=1..23) ; # R. J. Mathar, Jul 31 2007

Formula

For n>1, a(n) = (Sum_{r=1..n-1} binomial(n+1,r+1)*binomial(n+1,r)*a(r)*a(n-r))/(n+1)^2. - Michel Marcus, Oct 17 2012

Extensions

More terms from R. J. Mathar, Jul 31 2007