OFFSET
0,3
LINKS
Paul D. Hanna, Table of n, a(n) for n = 0..200
EXAMPLE
G.f.: A(x) = 1 + x - 2*x^2 + x^3 - x^4 + x^7 - 2*x^8 - x^9 - 2*x^10 + x^11 + 2*x^13 - x^14 + 2*x^16 - x^18 + x^19 - x^20 +...
where the following series consists entirely of integer coefficients:
(A(x^5) + 5*x)^(1/5) = 1 + x - 2*x^2 + 6*x^3 - 21*x^4 + 80*x^5 - 320*x^6 + 1326*x^7 - 5637*x^8 + 24434*x^9 - 107542*x^10 +...+ A196345(n)*x^n +...
PROG
(PARI) {a(n)=local(A=1+5*x); if(n==0, 1, for(j=1, 5*n, for(k=-2, 2, t=polcoeff((A+k*x^j+x*O(x^j))^(1/5), j);
if(denominator(t)==1, A=A+k*x^j; break))); polcoeff(A+x*O(x^(5*n)), 5*n))}
CROSSREFS
KEYWORD
sign
AUTHOR
Paul D. Hanna, Oct 01 2011
STATUS
approved