Expansion of Product_{m>=1} (1 + m*q^m)^15.

Terms

a(0) =1a(1) =15a(2) =135a(3) =950a(4) =5670a(5) =30003a(6) =144680a(7) =647055a(8) =2717760a(9) =10820640a(10) =41128374a(11) =150073470a(12) =528074655a(13) =1798537380a(14) =5947216050a(15) =19142919543a(16) =60113026305a(17) =184513760775a(18) =554517086825