Quaternary

The Base 4 method of counting in which only the Digits 0, 1, 2, and 3 are used. These Digits have the following multiplication table.

$\times$	0	1	2	3
0	0	0	0	0
1	0	1	2	3
2	0	2	10	12
3	0	3	12	21

See also Base (Number), Binary, Decimal, Hexadecimal, Octal, Ternary

References

Lauwerier, H. Fractals: Endlessly Repeated Geometric Figures. Princeton, NJ: Princeton University Press, pp. 9-10, 1991.

Weisstein, E. W. ``Bases.'' Mathematica notebook Bases.m.