OFFSET
0,4
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..286
FORMULA
E.g.f. satisfies: A(x) = 1 + Integral [1 + x*A(x)^3] dx.
a(n) ~ n^n / (exp(n) * r^(n+1)), where r = 0.69974580613381637... - Vaclav Kotesovec, Feb 24 2014
EXAMPLE
E.g.f.: A(x) = 1 + x + x^2/2! + 6*x^3/3! + 27*x^4/4! + 168*x^5/5! +...
A(x)^3 = 1 + 3*x + 9*x^2/2! + 42*x^3/3! + 279*x^4/4! + 2124*x^5/5! +...
x*A(x)^3 = x + 6*x^2/2! + 27*x^3/3! + 168*x^4/4! + 1395*x^5/5! +...
A'(x) = 1 + x + 6*x^2/2! + 27*x^3/3! + 168*x^4/4! + 1395*x^5/5! +...
PROG
(PARI) {a(n)=local(A=1+x); for(i=0, n, A=1+intformal(1+x*(A+x*O(x^n))^3)); n!*polcoeff(A, n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Sep 10 2008
STATUS
approved