Expansion of Sum_{k>=0} x^(k*(k+1)/2) / Product_{j=1..k} (1 + j*x^j).

Terms

a(0) =1a(1) =1a(2) =-1a(3) =2a(4) =-2a(5) =0a(6) =1a(7) =3a(8) =-5a(9) =-6a(10) =11a(11) =11a(12) =-12a(13) =-35a(14) =33a(15) =35a(16) =-22a(17) =-102a(18) =170a(19) =47a(20) =-224a(21) =-491a(22) =874a(23) =695a(24) =-598a(25) =-2606a(26) =2246a(27) =1503a(28) =-664a(29) =-6420