Expansion of Product_{k>=1} (1-x^k)^64.

Terms

a(0) =1a(1) =-64a(2) =1952a(3) =-37632a(4) =512400a(5) =-5207936a(6) =40618368a(7) =-244952576a(8) =1124362248a(9) =-3684692800a(10) =6607738816a(11) =8603838208a(12) =-109557823168a(13) =389162471040a(14) =-599467398400a(15) =-815811136000