n! in base 8.

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =30a(5) =170a(6) =1320a(7) =11660a(8) =116600a(9) =1304600a(10) =15657400a(11) =230212400a(12) =3443176000a(13) =56312146000