OFFSET
0,2
COMMENTS
Self-convolution of A240996.
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..250
FORMULA
G.f. satisfies: (A(x)-x)^2 = A(x*A(x)). - Paul D. Hanna, Oct 15 2003
a(n) ~ c * 2^(n+1) * n^(n - 1/2 - log(2)/4) / (exp(n) * (log(2))^n), where c = 0.411579248322849751402... (see A240996). - Vaclav Kotesovec, Feb 11 2015
PROG
(PARI) {a(n)=local(A, m); if(n<1, n==0, m=1; A=1+x; for(i=1, n, A=subst(A, x, x*A+x*O(x^n))/(A-x) + x); polcoeff(A, n))}
for(n=0, 20, print1(a(n), ", ")) \\ Vaclav Kotesovec, Feb 11 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Michael Somos, Sep 24 2003
STATUS
approved