G.f.: exp( Sum_{n>=1} A174466(n)*x^n/n ) where A174466(n) = Sum_{d|n} d*sigma(n/d)*tau(d).

Terms

a(0) =1a(1) =1a(2) =4a(3) =7a(4) =19a(5) =31a(6) =74a(7) =122a(8) =258a(9) =430a(10) =835a(11) =1378a(12) =2557a(13) =4162a(14) =7382a(15) =11932a(16) =20471a(17) =32676a(18) =54634a(19) =86251a(20) =141001a(21) =220371a(22) =353413a(23) =546783a(24) =863043a(25) =1322425a(26) =2057525a(27) =3125092a(28) =4801297a(29) =7230393