Expansion of Product_{k>=1} (1 - x^k)^13.

Terms

a(0) =1a(1) =-13a(2) =65a(3) =-130a(4) =-65a(5) =728a(6) =-871a(7) =-715a(8) =1560a(9) =845a(10) =78a(11) =-6513a(12) =2730a(13) =8605a(14) =-4355a(15) =2483a(16) =-13299a(17) =-2275a(18) =11440a(19) =10010a(20) =19734a(21) =-41834a(22) =-11375a(23) =12870a(24) =-2730a(25) =14911a(26) =33201a(27) =25155a(28) =-70070a(29) =-36595