a(n) = T(5,n), array T given by A048472.

Terms

a(0) =1a(1) =7a(2) =25a(3) =73a(4) =193a(5) =481a(6) =1153a(7) =2689a(8) =6145a(9) =13825a(10) =30721a(11) =67585a(12) =147457a(13) =319489a(14) =688129a(15) =1474561a(16) =3145729a(17) =6684673a(18) =14155777a(19) =29884417a(20) =62914561a(21) =132120577a(22) =276824065a(23) =578813953a(24) =1207959553a(25) =2516582401a(26) =5234491393a(27) =10871635969a(28) =22548578305a(29) =46707769345