a(n) = [x^n] exp(Sum_{k>=1} sigma_n(k)*x^k/(k*(1 - x)^k)).

A320569

a(n) = [x^n] exp(Sum_{k>=1} sigma_n(k)*x^k/(k*(1 - x)^k)).

Terms

    a(0) =1a(1) =1a(2) =4a(3) =25a(4) =272a(5) =5028a(6) =173754a(7) =11639691a(8) =1488266409a(9) =375932630887

External references