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

Terms

a(0) =1a(1) =-2a(2) =2a(3) =-2a(4) =4a(5) =-10a(6) =22a(7) =-42a(8) =72a(9) =-116a(10) =188a(11) =-332a(12) =662a(13) =-1432a(14) =3148a(15) =-6736a(16) =13784a(17) =-26894a(18) =50254a(19) =-90782a(20) =160856a(21) =-285230a(22) =518170a(23) =-983710a(24) =1964800a(25) =-4090002a(26) =8705322a(27) =-18582722a(28) =39219572a(29) =-81148034