Duplicate of A054661.

Terms

a(0) =1a(1) =0a(2) =5a(3) =12a(4) =51a(5) =160a(6) =585a(7) =2016a(8) =7280a(9) =26112a(10) =95325a(11) =349180a(12) =1290555a(13) =4792320