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Counting Digit Patterns with a Product Bound

Combinatorics · Math Count PH 2026 1667
How many 5-digit positive integers in the form $C\,A\,N\,O\,N$, where $C$, $A$, $N$, and $O$ represent distinct digits with $C > 0$, are there such that $C \times A \times N \times O \times N$ is less than 22?