Least m such that phi(m) = n!.

Terms

a(0) =1a(1) =3a(2) =7a(3) =35a(4) =143a(5) =779a(6) =5183a(7) =40723a(8) =364087a(9) =3632617a(10) =39916801a(11) =479045521a(12) =6227180929a(13) =87178882081