G.f.: exp( Sum_{n>=1} A174937(n)*x^n/n ) where A174937(n) = Sum_{d|n} d^tau(d).

Terms

a(0) =1a(1) =1a(2) =3a(3) =6a(4) =25a(5) =36a(6) =294a(7) =368a(8) =1528a(9) =2484a(10) =9134a(11) =14149a(12) =309394a(13) =338144a(14) =1088916a(15) =2036379a(16) =8135079a(17) =11985949a(18) =85274614a(19) =109840952a(20) =443748960a(21) =721070985a(22) =2618157358a(23) =4074809442a(24) =52689585877a(25) =60956862781a(26) =202828562711