a(n) = 7*a(n-1) - a(n-2) + 5.

Terms

a(0) =2a(1) =20a(2) =143a(3) =986a(4) =6764a(5) =46367a(6) =317810a(7) =2178308a(8) =14930351a(9) =102334154a(10) =701408732a(11) =4807526975a(12) =32951280098a(13) =225851433716