
Emirp Primes - headalgorithm
https://en.wikipedia.org/wiki/Emirp
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taberiand
Is this sort of toying with numbers just for fun, or does it in fact reveal
something interesting about primes or mathematics in general?

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pmiller2
Sounds 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.

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jey
What's so special about base 10 other than that it's the number of fingers
that humans (usually) have?

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etaioinshrdlu
I do also find the amount of recreational math focused on base 10 to be
disproportionate to the interestingness of base 10.

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tempguy9999
Come 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?

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etaioinshrdlu
The one true number base: [https://en.m.wikipedia.org/wiki/Quater-
imaginary_base](https://en.m.wikipedia.org/wiki/Quater-imaginary_base)

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0x8BADF00D
Is 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?

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emirp
I 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.

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saagarjha
Proposal to define "primemirp" as a prime that is also a palindrome.

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__init
Looks like those are already called "palprimes" [0].

[0]
[https://en.wikipedia.org/wiki/Palindromic_prime](https://en.wikipedia.org/wiki/Palindromic_prime)

