A159604 G.f.: A(x) = exp( Sum_{n>=1} [ Sum_{k>=1} sigma(n,k)*x^k ]^n/n ).
1, 1, 6, 43, 856, 10744, 608375, 14284223, 551011548, 19119025101, 874788949035, 37896009869060, 20683158266928833, 1799893777863733707, 93147805938921355288, 3757831283217050847983, 180287028377782585130749
Offset: 0
Keywords
Examples
G.f.: A(x) = 1 + x + 6*x^2 + 43*x^3 + 856*x^4 + 10744*x^5 +...
log(A(x)) = Sum_{n>=1} [sigma(n)*x + sigma(n,2)*x^2 + sigma(n,3)*x^3 +...]^n/n.
Links
- Paul D. Hanna, Table of n, a(n) for n = 0..510
Programs
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PARI
{a(n)=local(A=1+x);for(i=1,n,A=exp(sum(m=1,n,sum(k=1,n,sigma(m,k)*x^k+x*O(x^n))^m/m)));polcoeff(A,n)} for(n=0,20,print1(a(n),", "))
Comments