L.g.f.: -log(1 - Sum_{n>=1} x^(n*(n+1)/2)) = Sum_{n>=1} a(n)*x^n/n.

Terms

a(0) =1a(1) =1a(2) =4a(3) =5a(4) =6a(5) =16a(6) =22a(7) =29a(8) =49a(9) =86a(10) =122a(11) =188a(12) =300a(13) =456a(14) =714a(15) =1117a(16) =1718a(17) =2653a(18) =4124a(19) =6390a(20) =9916a(21) =15368a(22) =23806a(23) =36884a(24) =57181a(25) =88622a(26) =137344a(27) =212896a(28) =329934a(29) =511316