Owlet puzzle #20
Released Saturday, July 25, 2026 UTC
41
the answer for puzzle #20
The five clues
- A two-digit prime.
- A prime that appears in a famous Euler polynomial notable for producing many primes.
- Euler's famous prime-generating quadratic.
- The polynomial's constant term — its value at n = 0.
- At n = 40, we get 41², the first composite in the sequence.
Backstory
Euler's polynomial n² + n + 41 is prime for all n from 0 to 39 — a striking example of a formula that generates many primes without generating them all. It fails at n=40, giving 1681 = 41². Related to the class number of Q(√−163).
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