Permutations of 3 things

How many ways can we arrange three things in various numbers in a number of containers/boxes?
Enter in each box below a number <64 for:

The Number of possible arrangements is then:
of which one such arrangement is shown at right (click button again for another arrangement). The number or possible arrangements is calculated from the following equation:

where n is 6 squares, a is 2 o's, b is 2 x's, and c is 2 blank boxes. Any n up to 64 is possible here, with a, b, and c adding up to 64. Pretty cool. Try low numbers, even 0, and check me.
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