a(n) = floor(7^n/n).

Terms

a(0) =7a(1) =24a(2) =114a(3) =600a(4) =3361a(5) =19608a(6) =117649a(7) =720600a(8) =4483734a(9) =28247524a(10) =179756976a(11) =1153440600a(12) =7453000800a(13) =48444505203a(14) =316504100662