> If you multiply in base 18, the answer to 4 times 5 is 20, which is written "12" (one eighteen plus two). In base 21, the answer to 4 times 6 is 24, written "13" (one twenty-one plus three). The pattern continues. In base 24, 4 times 7 is 28, written "14." Each step up advances the multiplication base by three. The product, written in that new base, always falls one short of twenty.

The product is always 1 and some other digit but not one short of 20

And we only have two multiplications with their result, that’s hardly a pattern