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

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =13a(5) =36a(6) =107a(7) =343a(8) =1184a(9) =4391a(10) =17448a(11) =74082a(12) =335131a(13) =1610301a(14) =8191728a(15) =43973853a(16) =248305235a(17) =1470474074a(18) =9107950029a(19) =58856529464a(20) =395914407606