G.f.: Product_{k>=1} 1/(1-x^k)^(3*k+2).

Terms

a(0) =1a(1) =5a(2) =23a(3) =86a(4) =295a(5) =926a(6) =2748a(7) =7732a(8) =20891a(9) =54401a(10) =137355a(11) =337249a(12) =808043a(13) =1893402a(14) =4348634a(15) =9805669a(16) =21741925a(17) =47463473a(18) =102133056a(19) =216841459a(20) =454648373a(21) =942113618a(22) =1930779697a(23) =3915946921a(24) =7864385266a(25) =15647363323a(26) =30858285440a(27) =60345383394a(28) =117065924679