a(n) = T(5,n), array T given by A048471.

Terms

a(0) =1a(1) =33a(2) =129a(3) =417a(4) =1281a(5) =3873a(6) =11649a(7) =34977a(8) =104961a(9) =314913a(10) =944769a(11) =2834337a(12) =8503041a(13) =25509153a(14) =76527489a(15) =229582497a(16) =688747521a(17) =2066242593a(18) =6198727809a(19) =18596183457a(20) =55788550401a(21) =167365651233a(22) =502096953729