Expansion of Product_{k>=1} (1 - 3*x^k)/(1 + 3*x^k).

Terms

a(0) =1a(1) =-6a(2) =12a(3) =-24a(4) =102a(5) =-312a(6) =840a(7) =-2544a(8) =7788a(9) =-23406a(10) =69816a(11) =-208968a(12) =628536a(13) =-1886712a(14) =5654784a(15) =-16961856a(16) =50900934a(17) =-152709936a(18) =458084244a(19) =-1374231912a(20) =4122828408a(21) =-12368549040a(22) =37105252680a(23) =-111315549552a(24) =333947845416