OFFSET
0,2
EXAMPLE
A(x)^3 = 1 + 9*x + 3*x^3 - 9*x^6 + 46*x^9 - 276*x^12 + 1827*x^15 -+...
A(x^3) = 1 + 3*x^3 - 9*x^6 + 46*x^9 - 276*x^12 + 1827*x^15 -+...
PROG
(PARI) {a(n)=local(A=1+x); for(i=1, n, A=(subst(A, x, x^3)+9*x+x*O(x^n))^(1/3)); polcoeff(A, n, x)}
CROSSREFS
KEYWORD
sign
AUTHOR
Paul D. Hanna, May 11 2005
STATUS
approved