a(n) = (n^2)! / (n^2-n)! = number of ways of placing n labeled balls into n^2 labeled boxes with at most one ball in each box.

A227052

a(n) = (n^2)! / (n^2-n)! = number of ways of placing n labeled balls into n^2 labeled boxes with at most one ball in each box.

Terms

    a(0) =1a(1) =1a(2) =12a(3) =504a(4) =43680a(5) =6375600a(6) =1402410240a(7) =432938943360

External references