OFFSET
1,3
EXAMPLE
A(x) = x + x^2 - 3*x^3 + 17*x^4 - 115*x^5 + 841*x^6 -6288*x^7 +...
where A(A(A(A(A(x))))) =
x + 5*x^2 + 5*x^3 + 5*x^4 + 5*x^5 + 5*x^6 + 4*x^7 + 3*x^8 +...
is the g.f. of A112110.
PROG
(PARI) {a(n, m=5)=local(F=x+x^2+x*O(x^n), G); if(n<1, 0, for(k=3, n, G=F+x*O(x^k); for(i=1, m-1, G=subst(F, x, G)); F=F-((polcoeff(G, k)-1)\m)*x^k); return(polcoeff(F, n, x)))}
CROSSREFS
KEYWORD
sign
AUTHOR
Paul D. Hanna, Aug 27 2005
STATUS
approved