[xarope]

Proofs need to be comprehensive.

Here's a silly one: since 1, 3, 5 and 7 are primes, it almost seems obvious that all odd numbers are prime. Naturally, they are not, and there are countless proofs about various prime number generators to show that they can generate prime numbers, which are really prime.

[saagarjha]

1 is not prime.

[ezequiel-garzon]

I agree, modern definitions exclude 1 since "we lose" unique factorization. It's interesting to note [1] that this viewpoint solidified only in the last century.

[1] https://mathenchant.wordpress.com/2025/04/21/is-1-prime-and-...

[xarope]

darn, I just dated myself back to 1914...