threelonmusketeers to Math [email protected]English • 10 hours agoJohn Conway proves that 91 is the smallest number which looks prime but isn'twww.youtube.comexternal-linkmessage-square16fedilinkarrow-up180arrow-down13
arrow-up177arrow-down1external-linkJohn Conway proves that 91 is the smallest number which looks prime but isn'twww.youtube.comthreelonmusketeers to Math [email protected]English • 10 hours agomessage-square16fedilink
minus-squarethreelonmusketeersOPlinkfedilinkEnglish3•edit-23 hours ago 21 should be 2 + 1 = 3, therefore 21 is divisible by 3 and is not prime. QED :)
minus-square@[email protected]linkfedilinkEnglish1•3 hours ago9+1 = 10, therefore 91 is divisible by 10 and is not a prime … QED, I guess
I always felt that 21 should be, but nooo. Stupid 7
2 + 1 = 3, therefore 21 is divisible by 3 and is not prime. QED :)
9+1 = 10, therefore 91 is divisible by 10 and is not a prime … QED, I guess