G.f.: [ Sum_{n>=0} x^n * (1+x)^(n^2) ] * [ Sum_{n>=0} x^n / (1+x)^(n^2) ].

A320950

G.f.: [ Sum_{n>=0} x^n * (1+x)^(n^2) ] * [ Sum_{n>=0} x^n / (1+x)^(n^2) ].

Terms

    a(0) =1a(1) =2a(2) =3a(3) =5a(4) =20a(5) =81a(6) =272a(7) =1144a(8) =6147a(9) =30859a(10) =158137a(11) =955988a(12) =5995439a(13) =37307475a(14) =252176301a(15) =1813873656a(16) =13149151909a(17) =99412177075a(18) =793516947530

External references