G.f.: A(x) = exp( Sum_{n>=1} [ Sum_{k>=1} sigma(k,n)*x^k ]^n/n ).
A159595
G.f.: A(x) = exp( Sum_{n>=1} [ Sum_{k>=1} sigma(k,n)*x^k ]^n/n ).
Terms
- a(0) =1a(1) =1a(2) =4a(3) =13a(4) =56a(5) =286a(6) =2008a(7) =19749a(8) =280842a(9) =5762129a(10) =168873970a(11) =7023348917a(12) =412682000624
External references
- oeis: A159595