a(n) = A188526(n)/7.

Terms

a(0) =4a(1) =35a(2) =313a(3) =2813a(4) =25309a(5) =227765a(6) =2049853a(7) =18448613a(8) =166037389a(9) =1494336245a(10) =13449025693a(11) =121041230213