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

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =1a(5) =2a(6) =4a(7) =5a(8) =7a(9) =10a(10) =15a(11) =18a(12) =25a(13) =31a(14) =41a(15) =53a(16) =66a(17) =81a(18) =103a(19) =125a(20) =154a(21) =190a(22) =229a(23) =276a(24) =333a(25) =399a(26) =475a(27) =568a(28) =673a(29) =794