A027096 a(n) = A027082(n, 2n-9).
1, 3, 9, 31, 105, 355, 1198, 4024, 13429, 44479, 146145, 476347, 1540615, 4946425, 15774197, 49992571, 157545775, 493946713, 1541481630, 4790452228, 14831036177, 45759663403, 140751744489, 431730577935, 1320914941797
Offset: 5