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

Terms

a(0) =1a(1) =2a(2) =8a(3) =26a(4) =76a(5) =216a(6) =590a(7) =1554a(8) =3988a(9) =9988a(10) =24464a(11) =58794a(12) =138866a(13) =322808a(14) =739658a(15) =1672372a(16) =3734848a(17) =8245956a(18) =18012114a(19) =38952586a(20) =83448832a(21) =177194716a(22) =373111970a(23) =779430870a(24) =1615995262a(25) =3326484686a(26) =6800794428a(27) =13813260736a(28) =27881653590a(29) =55942340000