Largest square <= n!.

Terms

a(0) =1a(1) =1a(2) =1a(3) =4a(4) =16a(5) =100a(6) =676a(7) =4900a(8) =40000a(9) =362404a(10) =3625216a(11) =39904489a(12) =478996996a(13) =6226945921a(14) =87177877081