OFFSET
0,3
COMMENTS
See comments in A090353.
PROG
(PARI) {a(n)=local(A); if(n<1, 0, A=1+x+x*O(x^n); for(k=1, n, B=subst(A^3, x, x/(1-x))/(1-x)+x*O(x^n); A=A-A^4+B); B=subst(A, x, x/(1-x))/(1-x)+x*O(x^n); polcoeff(B^(1/2), n, x))}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Nov 26 2003
STATUS
approved