G.f.: Sum_{n>=0} (n+1)*(n+2)*(n+3)*(n+4)/4! * x^n * (1 + x^n)^n.

Terms

a(0) =1a(1) =5a(2) =20a(3) =35a(4) =100a(5) =126a(6) =330a(7) =330a(8) =775a(9) =820a(10) =1631a(11) =1365a(12) =3535a(13) =2380a(14) =5370a(15) =5136a(16) =9085a(17) =5985a(18) =16900a(19) =8855a(20) =21966a(21) =19580a(22) =29965a(23) =17550a(24) =60375a(25) =24381a(26) =58345a(27) =57205a(28) =90350a(29) =40920