Number of vertically indecomposable distributive lattices on n nodes.

Terms

a(0) =0a(1) =1a(2) =0a(3) =1a(4) =0a(5) =1a(6) =0a(7) =3a(8) =1a(9) =6a(10) =2a(11) =16a(12) =8a(13) =42a(14) =28a(15) =112a(16) =93a(17) =311a(18) =295a(19) =869a(20) =939a(21) =2454a(22) =2931a(23) =7032a(24) =9036a(25) =20301a(26) =27701a(27) =58929a(28) =84413a(29) =172104