(A192377)/2.

Terms

a(0) =0a(1) =1a(2) =2a(3) =10a(4) =34a(5) =131a(6) =484a(7) =1812a(8) =6756a(9) =25221a(10) =94118a(11) =351262a(12) =1310918a(13) =4892423a(14) =18258760a(15) =68142632a(16) =254311752a(17) =949104393a(18) =3542105802a(19) =13219318834a(20) =49335169514a(21) =184121359243a(22) =687150267436