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

Terms

a(0) =1a(1) =1a(2) =4a(3) =10a(4) =26a(5) =59a(6) =141a(7) =310a(8) =692a(9) =1483a(10) =3162a(11) =6583a(12) =13602a(13) =27613a(14) =55579a(15) =110445a(16) =217554a(17) =424148a(18) =820294a(19) =1572647a(20) =2992892a(21) =5652954a(22) =10605608a(23) =19765082a(24) =36609945a(25) =67405569a(26) =123412204a(27) =224728451a(28) =407119735a(29) =733878402