The nearest perfect square to n!

Terms

a(0) =1a(1) =1a(2) =1a(3) =4a(4) =25a(5) =121a(6) =729a(7) =5041a(8) =40401a(9) =362404a(10) =3629025a(11) =39917124a(12) =478996996a(13) =6226945921a(14) =87178467600