Largest square dividing n!.

Terms

a(0) =1a(1) =1a(2) =1a(3) =4a(4) =4a(5) =144a(6) =144a(7) =576a(8) =5184a(9) =518400a(10) =518400a(11) =2073600a(12) =2073600a(13) =101606400a(14) =914457600a(15) =14631321600a(16) =14631321600a(17) =526727577600a(18) =526727577600