OFFSET
0,3
EXAMPLE
A(x) = 1 + x - 3*x^2 + 13*x^3 - 65*x^4 + 351*x^5 - 1989*x^6 +-...
A(x)^7 = 1 + 7*x + x^7 + 4*x^14 + 6*x^21 + 5*x^28 + x^35 + 6*x^42 +...
A106226 = {1,7,0,0,0,0,0,1,0,0,0,0,0,0,4,0,0,0,0,0,0,6,...}.
PROG
(PARI) {a(n)=local(A=1+7*x); if(n==0, 1, for(j=1, n, for(k=0, 6, t=polcoeff((A+k*x^j+x*O(x^j))^(1/7), j); if(denominator(t)==1, A=A+k*x^j; break))); return(polcoeff((A+x*O(x^n))^(1/7), n)))}
CROSSREFS
KEYWORD
sign,base
AUTHOR
Paul D. Hanna, May 01 2005
STATUS
approved