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

Terms

a(0) =1a(1) =2a(2) =7a(3) =32a(4) =131a(5) =562a(6) =2383a(7) =10124a(8) =42916a(9) =181844a(10) =769246a(11) =3250388a(12) =13716377a(13) =57812466a(14) =243382957a(15) =1023463628a(16) =4299199426a(17) =18040918456a(18) =75632083258a(19) =316774424568