Expansion of Product_{k>=1} 1/(1 - x^k)^(sigma_2(k)).

Terms

a(0) =1a(1) =1a(2) =6a(3) =16a(4) =52a(5) =128a(6) =373a(7) =913a(8) =2399a(9) =5796a(10) =14298a(11) =33655a(12) =79756a(13) =183078a(14) =419846a(15) =942807a(16) =2106176a(17) =4633208a(18) =10127557a(19) =21870997a(20) =46912648a(21) =99639685a(22) =210206722a(23) =439777198a(24) =914157490a(25) =1886428608a(26) =3869204040a(27) =7884691072a(28) =15976273573a(29) =32182538964