This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A065724 #20 Jul 17 2025 16:17:24 %S A065724 2,3,5,7,19,37,67,79,97,103,127,157,163,193,229,283,307,337,439,487, %T A065724 547,571,601,631,643,673,733,751,757,853,877,907,937,1021,1033,1039, %U A065724 1087,1093,1117,1171,1249,1279,1423,1567,1627,1663,1723,1753,1831,1873 %N A065724 Primes p such that the decimal expansion of its base-6 conversion is also prime. %C A065724 In general rebase notation (Marc LeBrun): p6 = (6) [p] (10). %H A065724 Harry J. Smith, <a href="/A065724/b065724.txt">Table of n, a(n) for n = 1..1000</a> %e A065724 E.g., 1627_10 = 11311_6 is prime, and so is 11311_10. %t A065724 Select[ Range[1900], PrimeQ[ # ] && PrimeQ[ FromDigits[ IntegerDigits[ #, 6]]] & ] %t A065724 Select[Prime[Range[300]],PrimeQ[FromDigits[IntegerDigits[#,6]]]&] (* _Harvey P. Dale_, Jul 17 2025 *) %o A065724 (PARI) isok(p) = isprime(p) && isprime(fromdigits(digits(p, 6), 10)); \\ _Michel Marcus_, Mar 05 2022 %Y A065724 Primes in A036959. %Y A065724 Cf. A065720 up to A065727, A065361. %K A065724 nonn,base %O A065724 1,1 %A A065724 _Patrick De Geest_, Nov 15 2001