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.

A090359 Self-convolution equals the binomial transform of A090358: A^2 = BINOMIAL(A090358), where A090358^6 = BINOMIAL(A090358^5).

Original entry on oeis.org

1, 1, 4, 40, 640, 13816, 374636, 12229364, 466769330, 20391705290, 1003264704212, 54885373562372, 3304609250020008, 217139910688424400, 15461303963210314980, 1185856988993966140380, 97466557932008735970465
Offset: 0

Views

Author

Paul D. Hanna, Nov 26 2003

Keywords

Comments

See comments in A090358.

Crossrefs

Cf. A090358.

Programs

  • PARI
    {a(n)=local(A); if(n<1,0,A=1+x+x*O(x^n); for(k=1,n,B=subst(A^5,x,x/(1-x))/(1-x)+x*O(x^n); A=A-A^6+B);B=subst(A,x,x/(1-x))/(1-x)+x*O(x^n); polcoeff(B^(1/2),n,x))}

Formula

a(n) ~ (n-1)! / (50 * (log(6/5))^(n+1)). - Vaclav Kotesovec, Nov 19 2014