Ceiling of Gamma(n+6/7)/Gamma(6/7).

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =18a(5) =86a(6) =500a(7) =3423a(8) =26889a(9) =238158a(10) =2347554a(11) =25487721a(12) =302211543a(13) =3885576979a(14) =53842995268a(15) =799953072549