Expansion of Product_{k>=1} ((1 + x^(4*k)) / (1 - x^k))^k.

Terms

a(0) =1a(1) =1a(2) =3a(3) =6a(4) =14a(5) =25a(6) =51a(7) =92a(8) =175a(9) =308a(10) =554a(11) =957a(12) =1670a(13) =2820a(14) =4778a(15) =7940a(16) =13169a(17) =21511a(18) =35032a(19) =56405a(20) =90453a(21) =143716a(22) =227342a(23) =356950a(24) =557977a(25) =866588a(26) =1340109a(27) =2060912a(28) =3156274a(29) =4810016