OFFSET
0,3
FORMULA
G.f. A(x) satisfies: A(x) = G(G(x)-1), A(G(x)-1) = G(A(x)-1), A(x) = G(x*A(x)^4) and A(x/G(x)^4) = G(x), where G(x) is the g.f. of A120974 and satisfies G(x/G(x)^4) = 1 + x.
PROG
(PARI) {a(n)=local(A, G=[1, 1]); for(i=1, n, G=concat(G, 0); G[ #G]=-Vec(subst(Ser(G), x, x/Ser(G)^4))[ #G]); A=Vec(((Ser(G)-1)/x)^(1/4)); A[n+1]}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jul 20 2006
STATUS
approved