OFFSET
1,3
FORMULA
G.f. A(x) satisfies:
(1) A(x) = x + Sum_{n>=1} (d/dx)^(n-1) ( x/(1+x)*A(x) )^n / n!.
(2) A(x) = x * exp( Sum_{n>=1} (d/dx)^(n-1) (1/x) * ( x/(1+x)*A(x) )^n / n! ).
EXAMPLE
G.f.: A(x) = x + x^2 + 2*x^3 + 7*x^4 + 31*x^5 + 159*x^6 + 909*x^7 + 5657*x^8 + 37750*x^9 + 267367*x^10 + 1995167*x^11 + 15601743*x^12 +...
PROG
(PARI) {a(n) = my(A=x); for(i=1, n, A = serreverse(x - x/(1+x)*A +x*O(x^n)) ); polcoeff(A, n)}
for(n=1, 30, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jun 10 2016
STATUS
approved