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.

A102224 Column 0 of the matrix square of A102220, which equals the lower triangular matrix: [2*I - A008459]^(-1).

Original entry on oeis.org

1, 2, 14, 200, 4814, 174752, 8909168, 606818060, 53211837134, 5838211285616, 783434682568664, 126221710572107900, 24043148814317769584, 5344827109234104188348, 1371307353540074156012828
Offset: 0

Views

Author

Paul D. Hanna, Dec 31 2004

Keywords

Comments

A102221 is column 0 of A102220.
Triangle A008459 consists of the squared binomial coefficients.

Examples

			Given A102221 = [1,1,5,55,1077,32951,1451723,87054773,...], then this sequence results from a type of self-convolution of A102221:
a(2) = 14 = 1^2*1*5 + 2^2*1*1 + 1^2*5*1,
a(3) = 200 = 1^2*1*55 + 3^2*1*5 + 3^2*5*1 + 1^2*55*1.
		

Crossrefs

Programs

  • PARI
    {a(n)=(matrix(n+1,n+1,i,j,if(i==j,2,0)-binomial(i-1,j-1)^2)^-2)[n+1,1]}

Formula

a(n) = Sum_{k=0..n} C(n, k)^2*A102221(k)*A102221(n-k).
Sum_{n>=0} a(n)*x^n/n!^2 = 1/(2-BesselI(0,2*sqrt(x)))^2. - Vladeta Jovovic, Jul 17 2006