Right edge of triangle in A059283.

Terms

a(0) =1a(1) =1a(2) =3a(3) =11a(4) =47a(5) =219a(6) =1081a(7) =5557a(8) =29439a(9) =159611a(10) =881405a(11) =4940385a(12) =28035205a(13) =160751005a(14) =929923395a(15) =5420717819a(16) =31809479855a(17) =187757573787