threelonmusketeers@sh.itjust.works to Math MemesEnglish · 8 months agoJohn Conway proves that 91 is the smallest number which looks prime but isn'twww.youtube.comexternal-linkmessage-square18linkfedilinkarrow-up1113
arrow-up1113external-linkJohn Conway proves that 91 is the smallest number which looks prime but isn'twww.youtube.comthreelonmusketeers@sh.itjust.works to Math MemesEnglish · 8 months agomessage-square18linkfedilink
minus-squareerie09@lemmy.worldlinkfedilinkEnglisharrow-up8·8 months agoI always felt that 21 should be, but nooo. Stupid 7
minus-squarethreelonmusketeers@sh.itjust.worksOPlinkfedilinkEnglisharrow-up5·edit-28 months ago 21 should be 2 + 1 = 3, therefore 21 is divisible by 3 and is not prime. QED :)
minus-squareBigDanishGuy@sh.itjust.workslinkfedilinkEnglisharrow-up6·8 months ago9+1 = 10, therefore 91 is divisible by 10 and is not a prime … QED, I guess
minus-squarehumorlessrepost@lemmy.worldlinkfedilinkEnglisharrow-up3·8 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.