Right edge of triangle A297495.

Terms

a(0) =1a(1) =2a(2) =5a(3) =12a(4) =28a(5) =66a(6) =154a(7) =348a(8) =762a(9) =1645a(10) =3569a(11) =7849a(12) =17418a(13) =38588a(14) =84611a(15) =183135a(16) =392475a(17) =838029a(18) =1793945a(19) =3863537a(20) =8369150a(21) =18177363a(22) =39421917a(23) =85087021a(24) =182500928a(25) =389187036a(26) =826803475a(27) =1754407220a(28) =3726873592a(29) =7935854531