%I #9 Oct 31 2014 17:04:48
%S 4,24,576,36972288,6268637952000
%N Number of 4X4X...X4 = 4^n arrays of 0's and 1's with exactly one 1 in each row, column, ..., line, ... .
%e a(2)=24 because these are the 4X4 0,1 matrices representing the permutations of 4 letters.
%Y Column 4 of array in A249026.
%K nonn,more
%O 1,1
%A _N. J. A. Sloane_, Oct 23 2014