Eigensequence of triangle A168258.

Terms

a(0) =1a(1) =2a(2) =6a(3) =14a(4) =38a(5) =96a(6) =254a(7) =656a(8) =1724a(9) =4492a(10) =11776a(11) =30774a(12) =80608a(13) =210892a(14) =552226a(15) =1445374a(16) =3784308a(17) =9906482a(18) =25936206a(19) =67899344a(20) =177764618a(21) =465387226a(22) =1218404344a(23) =3189806746a(24) =8351034954a(25) =21863248282a(26) =57238759726a(27) =149852900454a(28) =392320072078