Product_{k>=1} 1/(1 - a(k)*x^k) = 1 + Sum_{k>=1} k^2*x^k.

Terms

a(0) =1a(1) =3a(2) =5a(3) =-2a(4) =-6a(5) =-35a(6) =-4a(7) =8a(8) =16a(9) =-62a(10) =-158a(11) =-1149a(12) =56a(13) =556a(14) =680a(15) =-1566a(16) =-4966a(17) =3544a(18) =6132a(19) =20268a(20) =15792a(21) =-75194a(22) =-162814a(23) =-1246153a(24) =333904a(25) =805112a(26) =235968a(27) =-2775034a(28) =-5259270a(29) =7160120