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CircularPrimes ​

The circular primes 2,3,5,7,11,13,17,31,…2, 3, 5, 7, 11, 13, 17, 31, …: primes whose every base-10 digit rotation is also prime.

CircularPrimesthe prime pp (no digit 0) with every cyclic rotation of its decimal digits also prime, an indexed collection of open infinitude.

Domain: Collections

Details
  • A lazy indexed collection; conjectured but unproven that only finitely many beyond the repunit primes RnR_n (all-1s) exist at all, and separately whether infinitely many repunit primes exist is itself open, so Count(CircularPrimes)=NaNCount(CircularPrimes) = NaN. OEIS A068652. A digit-0 prime is excluded (a rotation would start with a leading zero).
  • At(CircularPrimes,k)At(CircularPrimes, k) unranks by scanning forward, testing every rotation's primality -- At(CircularPrimes,8)=31At(CircularPrimes, 8) = 31 (3131 and 1313 both prime).
  • Membership goes through Element: Element(13,CircularPrimes)Element(13, CircularPrimes) is true (13,3113, 31 both prime), Element(19,CircularPrimes)Element(19, CircularPrimes) is false (91=7×1391 = 7 \times 13, its only other rotation, isn't prime).

Enumeration

Examples

1 more kept as data, checked against the oracles
About
Examples1
CrosswalkOEIS

See also: Count, At, Element, PalindromicPrimes, EmirpPrimes