OFFSET
1,2
FORMULA
a(n) ~ A^2 * exp(n^2/2 + n - 1/12) / (n^(n/2 - 2/3) * (2*Pi)^((n+1)/2)), where A = A074962 = 1.2824271291... is the Glaisher-Kinkelin constant. - Vaclav Kotesovec, Jul 10 2015
EXAMPLE
L.g.f.: L(x) = x + 3*x^2/2 + 22*x^3/3 + 347*x^4/4 + 11986*x^5/5 + 956334*x^6/6 +...
where
exp(L(x)) = 1 + x + 2*x^2 + 9*x^3 + 96*x^4 + 2500*x^5 + 162000*x^6 + 26471025*x^7 + 11014635520*x^8 +...+ A001142(n)*x^n +...
MATHEMATICA
nmax=15; Rest[CoefficientList[Series[Log[Sum[Product[j^j/j!, {j, 1, k}]*x^k, {k, 0, nmax}]], {x, 0, nmax}], x] * Range[0, nmax]] (* Vaclav Kotesovec, Jul 10 2015 *)
PROG
(PARI) {a(n)=n*polcoeff(log(sum(k=0, n+1, prod(j=0, k, j^j/j!)*x^k)+x*O(x^n)), n)}
for(n=1, 21, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Nov 16 2012
STATUS
approved