a(n) = T(6,n), array T given by A048471.

Terms

a(0) =1a(1) =65a(2) =257a(3) =833a(4) =2561a(5) =7745a(6) =23297a(7) =69953a(8) =209921a(9) =629825a(10) =1889537a(11) =5668673a(12) =17006081a(13) =51018305a(14) =153054977a(15) =459164993a(16) =1377495041a(17) =4132485185a(18) =12397455617a(19) =37192366913a(20) =111577100801a(21) =334731302465