Number of closed typable lambda terms of size n with size 0 for the variables.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =0a(6) =1a(7) =1a(8) =1a(9) =1a(10) =5a(11) =4a(12) =9a(13) =13a(14) =23a(15) =29a(16) =67a(17) =94a(18) =179a(19) =285a(20) =503a(21) =795a(22) =1503a(23) =2469a(24) =4457a(25) =7624a(26) =13475a(27) =23027a(28) =41437a(29) =72165