Expansion of Product_{k>=1} (1 + x^(k^2))^2/(1 - x^(k^2))^2.

Terms

a(0) =1a(1) =4a(2) =8a(3) =12a(4) =20a(5) =36a(6) =56a(7) =76a(8) =104a(9) =152a(10) =216a(11) =284a(12) =364a(13) =484a(14) =648a(15) =828a(16) =1028a(17) =1300a(18) =1664a(19) =2076a(20) =2532a(21) =3108a(22) =3848a(23) =4700a(24) =5640a(25) =6776a(26) =8200a(27) =9848a(28) =11660a(29) =13796