Main diagonal of triangle A129577.

Terms

a(0) =1a(1) =1a(2) =3a(3) =11a(4) =46a(5) =213a(6) =1075a(7) =5854a(8) =34141a(9) =211974a(10) =1394115a(11) =9670976a(12) =70501776a(13) =538393812a(14) =4294921858a(15) =35702077464a(16) =308575560999