threelonmusketeers to Math Memes@lemmy.blahaj.zoneEnglish • 7 months agoJohn Conway proves that 91 is the smallest number which looks prime but isn'twww.youtube.commessage-square19fedilinkarrow-up1113arrow-down13
arrow-up1110arrow-down1external-linkJohn Conway proves that 91 is the smallest number which looks prime but isn'twww.youtube.comthreelonmusketeers to Math Memes@lemmy.blahaj.zoneEnglish • 7 months agomessage-square19fedilink
minus-square@erie09@lemmy.worldlinkfedilinkEnglish6•7 months agoI always felt that 21 should be, but nooo. Stupid 7
minus-squarethreelonmusketeersOPlinkfedilinkEnglish5•edit-27 months ago 21 should be 2 + 1 = 3, therefore 21 is divisible by 3 and is not prime. QED :)
minus-square@BigDanishGuy@sh.itjust.workslinkfedilinkEnglish-1•7 months ago9+1 = 10, therefore 91 is divisible by 10 and is not a prime … QED, I guess
minus-square@humorlessrepost@lemmy.worldlinkfedilinkEnglish3•7 months agoIn the right base, that might work.
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
In the right base, that might work.