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

Terms

a(0) =1a(1) =4a(2) =16a(3) =60a(4) =192a(5) =596a(6) =1776a(7) =5020a(8) =13760a(9) =36916a(10) =96336a(11) =246316a(12) =619392a(13) =1530548a(14) =3729392a(15) =8976364a(16) =21337920a(17) =50195268a(18) =116977232a(19) =270114764a(20) =618712640a(21) =1406843940a(22) =3176387120a(23) =7126185948a(24) =15894370816a(25) =35253947940a(26) =77796242768a(27) =170868178332a(28) =373606888128