A065724 Primes p such that the decimal expansion of its base-6 conversion is also prime.
2, 3, 5, 7, 19, 37, 67, 79, 97, 103, 127, 157, 163, 193, 229, 283, 307, 337, 439, 487, 547, 571, 601, 631, 643, 673, 733, 751, 757, 853, 877, 907, 937, 1021, 1033, 1039, 1087, 1093, 1117, 1171, 1249, 1279, 1423, 1567, 1627, 1663, 1723, 1753, 1831, 1873
Offset: 1
Examples
E.g., 1627_10 = 11311_6 is prime, and so is 11311_10.
Links
- Harry J. Smith, Table of n, a(n) for n = 1..1000
Programs
-
Mathematica
Select[ Range[1900], PrimeQ[ # ] && PrimeQ[ FromDigits[ IntegerDigits[ #, 6]]] & ] Select[Prime[Range[300]],PrimeQ[FromDigits[IntegerDigits[#,6]]]&] (* Harvey P. Dale, Jul 17 2025 *)
-
PARI
isok(p) = isprime(p) && isprime(fromdigits(digits(p, 6), 10)); \\ Michel Marcus, Mar 05 2022
Comments