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 A235631 #17 Jan 16 2022 23:27:23 %S A235631 2,3,5,11,13,23,29,31,43,61,71,79,89,107,109,113,137,139,163,173,193, %T A235631 223,239,251,271,281,283,313,317,347,383,431,439,461,467,491,499,541, %U A235631 557,593,607,641,659,661,691,701,743,761,853,863,881,919,971,997,1013,1031,1051,1061,1063 %N A235631 Primes whose base-6 representation is also the base-8 representation of a prime. %C A235631 This sequence is part of a two-dimensional array of sequences, given in the LINK, based on this same idea for any two different bases b, c > 1. Sequence A235265 and A235266 are the most elementary ones in this list. Sequences A089971, A089981 and A090707 through A090721, and sequences A065720 - A065727, follow the same idea with one base equal to 10. %H A235631 Giovanni Resta, <a href="/A235631/b235631.txt">Table of n, a(n) for n = 1..10000</a> %H A235631 M. F. Hasler, <a href="https://docs.google.com/document/d/10IM7fcAbB2tqRGuwfGvuEGUzD_IXbgXPDK0tfxN4M3o/pub">Primes whose base c expansion is also the base b expansion of a prime</a> %e A235631 11 = 15_6 and 15_8 = 13 are both prime, so 11 is a term. %t A235631 Select[Prime@Range@500, PrimeQ@FromDigits[IntegerDigits[#, 6], 8] &] (* _Giovanni Resta_, Sep 12 2019 *) %o A235631 (PARI) is(p,b=8,c=6)=isprime(vector(#d=digits(p,c),i,b^(#d-i))*d~)&&isprime(p) \\ Note: This code is only valid for b > c. %Y A235631 Cf. A235638, A235265, A235266, A152079, A235461 - A235482, A065720 - A065727, A235394, A235395, A089971 ⊂ A020449, A089981, A090707 - A091924, A235615 - A235639. See the LINK for further cross-references. %K A235631 nonn,base %O A235631 1,1 %A A235631 _M. F. Hasler_, Jan 13 2014