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

Terms

a(0) =1a(1) =1a(2) =3a(3) =6a(4) =12a(5) =23a(6) =45a(7) =80a(8) =145a(9) =256a(10) =446a(11) =761a(12) =1292a(13) =2154a(14) =3568a(15) =5842a(16) =9485a(17) =15261a(18) =24386a(19) =38647a(20) =60867a(21) =95212a(22) =148052a(23) =228860a(24) =351899a(25) =538186a(26) =819105a(27) =1240704a(28) =1870886a(29) =2808888