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Emirp Primes
- saagarjha 7y agoProposal to define "primemirp" as a prime that is also a palindrome.
- taberiand 7y agoIs this sort of toying with numbers just for fun, or does it in fact reveal something interesting about primes or mathematics in general?
- pmiller2 7y agoSounds like just a bit of fun to me. For one, emirp-hood depends on the number base, which means it’s not intrinsic to the number, but depends on some arbitrary choice of representation. Generally, things like that don’t indicate anything deep.
- 0x8BADF00D 7y agoIs there a better way to check for an emirp other than checking if the number is prime, and then checking if its reverse is also prime?
- emirp 7y agoI can think of a couple of things off the top of my head: - You can reject numbers that start with 2,4,5,6 or 8 since their reverse won't be prime. - If you're searching through a range of numbers for emirps avoid checking for the same pair twice. For example if you start at 1 and check for emirps, by the time you're checking 311 you've already checked 113 so you don't need to check 311.
- jey 7y agoWhat's so special about base 10 other than that it's the number of fingers that humans (usually) have?
- etaioinshrdlu 7y agoI do also find the amount of recreational math focused on base 10 to be disproportionate to the interestingness of base 10.
- tempguy9999 7y agoCome on, mate, don't tease me with that and not offer your suggestions! Fractional bases, negative bases, negative fractional bases, base e (supposed to be optimal IIRC), perhaps complex bases, summat weirder?
- etaioinshrdlu 7y agoThe one true number base: https://en.m.wikipedia.org/wiki/Quater-imaginary_base https://en.m.wikipedia.org/wiki/Quater-imaginary_base
- LeoPanthera 7y agoNothing. https://en.wikipedia.org/wiki/Decimal https://en.wikipedia.org/wiki/Decimal
- lifthrasiir 7y agoIt isn't, so OEIS [1] correctly tags this sequence as base-dependent (keyword "base") and has a similar sequence in base 2 [2]. [1] https://oeis.org/A006567 https://oeis.org/A006567 [2] https://oeis.org/A080790 https://oeis.org/A080790
- evanb 7y agoWell, it's the base in which we label all other bases. In base twelve, 'base 12'(decimal) is written 'base 10'! :D