Expansion of g.f.: Product_{k>=1} 1+k*x^k/(1-x^k)^2.

Terms

a(0) =1a(1) =1a(2) =4a(3) =8a(4) =19a(5) =36a(6) =76a(7) =142a(8) =272a(9) =496a(10) =900a(11) =1592a(12) =2784a(13) =4792a(14) =8138a(15) =13688a(16) =22703a(17) =37380a(18) =60838a(19) =98310a(20) =157298a(21) =250162a(22) =394332a(23) =618032a(24) =961512a(25) =1487563a(26) =2286610a(27) =3496776a(28) =5316666a(29) =8044598