a(n) = A011782(n) + A000219(n) - A000712(n).

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =1a(5) =4a(6) =15a(7) =40a(8) =103a(9) =238a(10) =531a(11) =1131a(12) =2362a(13) =4811a(14) =9694a(15) =19307a(16) =38243a(17) =75400a(18) =148443a(19) =291984a(20) =574724a(21) =1132368a(22) =2234617a(23) =4416937a(24) =8745567a(25) =17343737a(26) =34446090a(27) =68500682a(28) =136374947a(29) =271755878