OFFSET
1,3
EXAMPLE
G.f.: A(x) = x + x^2 + 2*x^3 + 5*x^4 + 16*x^5 + 55*x^6 + 211*x^7 + 858*x^8 + 3709*x^9 + 16799*x^10 + 79393*x^11 + 389476*x^12 + 1975794*x^13 + ...
such that
1 = (1 - A(x)) + x*(1 + x - A(x))^2 + x^2*(1 + 2*x - A(x))^3 + x^3*(1 + 3*x - A(x))^4 + x^4*(1 + 4*x - A(x))^5 + x^5*(1 + 5*x - A(x))^6 + ...
PROG
(PARI) {a(n) = my(A=[1]); for(i=1, n, A=concat(A, 0); A[#A] = polcoeff( sum(n=0, #A, x^n * ( (1 + n*x) - x*Ser(A) )^(n+1) ), #A) ); A[n+1]}
for(n=0, 30, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, May 14 2019
STATUS
approved