OFFSET
0,2
COMMENTS
FORMULA
A(z)=0 at z=-0.322846893915891638743032676733152456643928599...
EXAMPLE
A(x)^(1/3) = 1 + 1x - 1x^2 + 2x^3 - 4x^4 + 9x^5 - 21x^6 + 53x^6 -+...
PROG
(PARI) {a(n)=local(A=1+3*x); if(n==0, 1, if(n==1, 3, for(j=2, n, for(k=0, 2, t=polcoeff((A+k*x^j+x*O(x^j))^(1/3), j); if(denominator(t)==1, A=A+k*x^j; break))); polcoeff(A, n)))}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, May 01 2005
STATUS
approved