Owlet puzzle #20
Released Saturday, July 25, 2026 UTC
41
the answer for puzzle #20
The five clues
- A two-digit prime.
- n² + n + 41 yields a prime for n = 0, 1, 2, ..., 39.
- Euler's famous prime-generating quadratic.
- Discovered by Euler in 1772.
- At n = 40, we get 41², the first composite in the sequence.
Backstory
Euler's polynomial is a striking example of a formula that generates many primes without generating them all.
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