The idea popped into my head to look for numbers that together with their prime factors contain all the digits exactly once. This proved to be a relatively straight forward exercise. Up to one million, there are only eight numbers that qualify. These numbers together with their factorisations are as follows (permalink):
- \(10968 = 2^3 \times 3 \times 457 \)
- \(28651 = 7 \times 4093 \)
- \(43610 = 2 \times 5 \times 7^2 \times 89 \)
- \(48960 = 2^6 \times 3^2 \times 5 \times 17 \)
- \(50841 = 3^3 \times 7 \times 269 \)
- \(65821 = 7 \times 9403 \)
- \(80416 = 2^5 \times 7 \times 359 \)
- \(90584 = 2^3 \times 13^2 \times 67 \)
If repeated prime factors are disallowed, then only \(28651\) and \(65821\) qualify. These eight numbers, as I subsequently discovered, make up OEIS A124668:
A124668 | Numbers that together with their prime factors contain every digit exactly once. |
So this is the sequence with only eight members: 10968, 28651, 43610, 48960, 50841, 65821, 80416, 90584.
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