Why are all 6-digit Fredholm numbers composite?

If we have a 6 -digit fredholl number, all numbers must consist of 3 occurrences of digits A, and 3 occurrences of digits B. So a sum of their digits is 3a+3b 3a+3b=3(a+b) and this number is divisible by 3, Therefore any 6-digit fredholl number is divisible by 3. If a number is divisible by any other number than 1 and itself, we call that number a composite number.

Answered by mackiemesser | 2024-06-10

All 6-digit Fredholm numbers are composite because their digits consist of three of one digit and three of another, making the sum of the digits divisible by 3. Since the numbers are divisible by 3, they are not prime. Therefore, every 6-digit Fredholm number is composite.
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Answered by mackiemesser | 2024-12-23