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

Terms

a(0) =1a(1) =2a(2) =8a(3) =32a(4) =126a(5) =496a(6) =1952a(7) =7680a(8) =30216a(9) =118882a(10) =467728a(11) =1840224a(12) =7240160a(13) =28485616a(14) =112073536a(15) =440941056a(16) =1734834302a(17) =6825515600a(18) =26854243752a(19) =105655081568a(20) =415688349456