Expansion of (1-q)^k/Product_{j=1..k} (1-q^j) for k=6.

Terms

a(0) =1a(1) =-5a(2) =11a(3) =-14a(4) =12a(5) =-9a(6) =9a(7) =-13a(8) =20a(9) =-26a(10) =27a(11) =-25a(12) =26a(13) =-33a(14) =43a(15) =-49a(16) =47a(17) =-42a(18) =43a(19) =-53a(20) =67a(21) =-77a(22) =78a(23) =-73a(24) =72a(25) =-82a(26) =98a(27) =-108a(28) =107a(29) =-102