Show HN: mod((prime*prime-1)/12)
Looks like every prime number multiplied by himself minus 1 is exactly divisible by 12. Figured out that few months ago.
3 comments
[deleted]
(Except for the prime numbers 2 and 3, of course.)
11 x 10
23×22=506
506÷12=42.16666...
Nope.
This is why mathematical statements need proofs.
Nope.
This is why mathematical statements need proofs.
(23x23-1)/12 = 44.
[deleted]
(11x11-1)/12 = 10.
Ah you mean (p×(p–1))÷12=(p²–p)÷12.
In that case it’s just the old p=6n±1.
In that case it’s just the old p=6n±1.
elegant