The first, 20,  terms of the sequence of enumerating

          the number of, 1, by  n Latin rectangles (divided by n!) is

                       for n between 1 and , 20, equals

          [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]

                    This took , 0.016, seconds of CPU time