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

Terms

a(0) =1a(1) =3a(2) =12a(3) =39a(4) =117a(5) =331a(6) =893a(7) =2307a(8) =5766a(9) =13986a(10) =33046a(11) =76302a(12) =172567a(13) =383013a(14) =835731a(15) =1795236a(16) =3801105a(17) =7941439a(18) =16386777a(19) =33423342a(20) =67435311a(21) =134675784a(22) =266385932a(23) =522135379a(24) =1014643823a(25) =1955656848a(26) =3740191268a(27) =7100290646a(28) =13383997996a(29) =25058666367