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.

A221100 E.g.f. satisfies: A(x) = 1 + x*Sum_{n>=0} log(A(n*x))^n / n!.

Original entry on oeis.org

1, 1, 2, 15, 248, 8440, 513144, 52356122, 8677146176, 2287135119744, 948641529992880, 614727594325073592, 618434779929242165856, 960690586903797786948288, 2293100087767812293312717088, 8373182505242530234213019810880, 46591358758492418174191908438641664
Offset: 0

Views

Author

Paul D. Hanna, Jan 01 2013

Keywords

Examples

			E.g.f.: A(x) = 1 + x + 2*x^2/2! + 15*x^3/3! + 248*x^4/4! + 8440*x^5/5! +...
where
A(x) = 1 + x + x*log(A(x)) + x*log(A(2*x))^2/2! + x*log(A(3*x))^3/3! + x*log(A(4*x))^4/4! + x*log(A(5*x))^5/5! +...
		

Crossrefs

Cf. A221101.

Programs

  • PARI
    {a(n)=local(A=1+x); for(i=1, n, A=1+x*sum(m=0, n, log( subst(A,x,m*x+x*O(x^n)) )^m/m!)); n!*polcoeff(A, n)}
    for(n=0,20,print1(a(n),", "))