OFFSET
1,2
LINKS
Paul D. Hanna, Table of n, a(n) for n = 1..120
FORMULA
EXAMPLE
G.f.: x = Sum_{n>=1} a(n) * (x + 2^n*x^2 + 3^n*x^3 +...+ k^n*x^k +...)^n.
The g.f. can be written using the Eulerian numbers like so:
x = x/(1-x)^2 - 2*(x + x^2)^2/(1-x)^6 + 13*(x + 4*x^2 + x^3)^3/(1-x)^12 - 248*(x + 11*x^2 + 11*x^3 + x^4)^4/(1-x)^20 + 12526*(x + 26*x^2 + 66*x^3 + 26*x^4 + x^5)^5/(1-x)^30 - 1568368*(x + 57*x^2 + 302*x^3 + 302*x^4 + 57*x^5 + x^6)^6/(1-x)^42 +...+ a(n)*[ Sum_{k=1..n} A008292(n,k) * x^k ]^n / (1-x)^(n*(n+1)) +...
PROG
(PARI) {a(n) = my(A=[1]); for(i=1, n, A = concat(A, 0);
A[#A] = -Vec(sum(m=1, #A, A[m]*sum(k=1, #A+1, k^m * x^k +x*O(x^#A))^m))[#A] ); A[n]}
for(n=1, 30, print1(a(n), ", "))
CROSSREFS
KEYWORD
sign
AUTHOR
Paul D. Hanna, Sep 29 2016
STATUS
approved