n! in base 7.

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =33a(5) =231a(6) =2046a(7) =20460a(8) =225360a(9) =3040650a(10) =42562410a(11) =663200340a(12) =14604306060a(13) =310211542410