Duplicate of A045924.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =10a(5) =70a(6) =72a(7) =182a(8) =440a(9) =1053a(10) =6458a(11) =6461a(12) =6471a(13) =40087a(14) =40089a(15) =251737