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

Terms

a(0) =1a(1) =2a(2) =10a(3) =36a(4) =118a(5) =376a(6) =1188a(7) =3456a(8) =10054a(9) =28814a(10) =79280a(11) =215844a(12) =581748a(13) =1528456a(14) =3987384a(15) =10295952a(16) =26130982a(17) =65874532a(18) =164661622a(19) =406787220a(20) =998529752a(21) =2434022304a(22) =5879630196a(23) =14124455856a(24) =33734350692a(25) =80000820426a(26) =188787849968a(27) =443372664504