A127783 G.f. satisfies: A(x) = 1 + x*A(x+x^2)^2.
1, 1, 2, 7, 28, 133, 700, 4039, 25160, 167637, 1186482, 8872752, 69810994, 575912978, 4967058182, 44675926159, 418157494016, 4065044047125, 40973402647058, 427535487044903, 4611642948647118, 51354908876927025
Offset: 0
Keywords
Links
- Vaclav Kotesovec, Table of n, a(n) for n = 0..310
Programs
-
PARI
{a(n)=local(A=1+x+x*O(x^n));for(i=0,n,A=1+x*subst(A^2,x,x+x^2));polcoeff(A,n)}