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

Terms

a(0) =1a(1) =-4a(2) =4a(3) =-4a(4) =20a(5) =-36a(6) =52a(7) =-116a(8) =244a(9) =-500a(10) =964a(11) =-1876a(12) =3876a(13) =-7780a(14) =15332a(15) =-30628a(16) =61684a(17) =-123460a(18) =246036a(19) =-491988a(20) =985492a(21) =-1971284a(22) =3939556a(23) =-7878068a(24) =15762692a(25) =-31527428a(26) =63041220a(27) =-126078916a(28) =252185044a(29) =-504375460