O.g.f.: exp( Sum_{n>=1} (sigma(2*n^3) - sigma(n^3)) * x^n/n ).

Terms

a(0) =1a(1) =2a(2) =10a(3) =44a(4) =134a(5) =468a(6) =1524a(7) =4584a(8) =13862a(9) =40566a(10) =114880a(11) =321052a(12) =879092a(13) =2360156a(14) =6248864a(15) =16297384a(16) =41902454a(17) =106437600a(18) =267149022a(19) =662979572a(20) =1628437160a(21) =3960377672a(22) =9541519732a(23) =22786066280a(24) =53958062564a(25) =126750346970a(26) =295476011176a(27) =683776368416