Uploaded May 2012 | Updated September 2026, 3 weeks ago
Here is a cute puzzle for those who have a predilection for the number three. Is there a number N so that it and all its multiples 2N, 3N, 4N, ... each contain the digit 3?
N=65913 gives a good run: N, 2N, 3N, .., 10N each contain the digit three, but 11N does not. Is there a "perfect" N with an infinitely long run of success?
Here is a cute puzzle for those who have a predilection for the number three. Is there a number N so that it and all its multiples 2N, 3N, 4N, ... each contain the digit 3?
N=65913 gives a good run: N, 2N, 3N, .., 10N each contain the digit three, but 11N does not. Is there a "perfect" N with an infinitely long run of success?
