E.g.f.: Product_{k>=1} (1 + x^(k*(k + 1)/2) / (k*(k + 1)/2)!).

Terms

a(0) =1a(1) =1a(2) =0a(3) =1a(4) =4a(5) =0a(6) =1a(7) =7a(8) =0a(9) =84a(10) =841a(11) =11a(12) =0a(13) =286a(14) =4004a(15) =1a(16) =8024a(17) =136136a(18) =816a(19) =7775256a(20) =155195040a(21) =54265a(22) =1193830a(23) =0a(24) =109832360a(25) =2749077760a(26) =84987760a(27) =296010a(28) =10716746041a(29) =310545275069