Normal sudoku rules apply.
If two digits are separated by a black dot, one is double the other.
The two grey cells contain the same digit.
Prime diagonals: The digits on each grey diagonal sum to a prime number, but no two diagonals sum to the same prime. (The primes from 1 to 100 are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97.)
Puzzle:
Solution code: Row 4 (from left to right)
on 6. February 2026, 18:01 by pep9
Thanks for pointing out! The link is now updated. (And you might be true... :D)
on 6. February 2026, 10:56 by superkinkel
Small correction for the wording: These are not the first 100 prime numbers, but either the first 25 or the ones below hundred. And something tells me we need less anyway ;-)
| Difficulty: | ![]() |
| Rating: | N/A |
| Solved: | 4 times |
| Observed: | 0 times |
| ID: | 000RBP |
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