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

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =7a(5) =12a(6) =22a(7) =43a(8) =85a(9) =164a(10) =308a(11) =573a(12) =1079a(13) =2081a(14) =4097a(15) =8129a(16) =16049a(17) =31315a(18) =60402a(19) =115806a(20) =222416a(21) =430791a(22) =843987a(23) =1670054a(24) =3322167a(25) =6606936a(26) =13078586a(27) =25714238a(28) =50230292a(29) =97708338