Incorrect version of A035010.

Terms

a(0) =1a(1) =2a(2) =4a(3) =38a(4) =132a(5) =420a(6) =1426a(7) =4834a(8) =16796a(9) =58688a(10) =208012a(11) =742636a(12) =2674384a(13) =9693976a(14) =35357670a(15) =129641774