PalindromicPrimes

The palindromic primes $2, 3, 5, 7, 11, 101, …$: primes that read the same forwards and backwards in base 10.

OEISA002385↗

PalindromicPrimesthe prime $p$ whose decimal digits are a palindrome, an indexed collection of open infinitude.

Domain: Collections

Details

• A lazy indexed collection; whether there are infinitely many (beyond the trivial even-length exclusion -- every palindrome with an even digit count past 11 is divisible by 11) is open, so $Count(PalindromicPrimes) = NaN$. OEIS A002385.
• $At(PalindromicPrimes, k)$ unranks by scanning forward, testing primality and digit-palindromy -- $At(PalindromicPrimes, 6) = 101$.
• Membership goes through Element: $Element(101, PalindromicPrimes)$ is true, $Element(103, PalindromicPrimes)$ is false ($103 \ne 301$).

Enumeration

Examples

1 more kept as data, checked against the oracles

About

Examples	1
Crosswalk	OEIS

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