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 A123266 #32 Mar 14 2023 10:02:32 %S A123266 5,1097,2237,2689,3541,12979,13477,22367,22783,27701,28499,33521, %T A123266 33613,43093,51839,55487,57383,65423,69931,70201,71429,74209,80599, %U A123266 82267,82889,83591,95009,99079,99881,105929,122201,123923,125261 %N A123266 Primes p such that the decimal expansion of p remains prime under two iterations of base-10 to base-2 conversions. %C A123266 More precisely, "... remains prime under two iterations of base-10 to base-2 conversions, but not three iterations." %C A123266 . %H A123266 Sebastian Petzelberger, <a href="/A123266/b123266.txt">Table of n, a(n) for n = 1..10000</a>. %H A123266 Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_280.htm">Puzzle 280. 3893257</a>, The Prime Puzzles & Problems Connection. %e A123266 5 is a term because 5_10 = 101_2 and 101_10 = 1100101_2 and both 101 and 1100101 are prime in base 10. %t A123266 okQ[n_] := And @@ PrimeQ[Rest[NestList[FromDigits[IntegerDigits[#, 2]] &, n, 2]]]; Select[Prime[Range[20000]], okQ] (* _Harvey P. Dale_, Jan 14 2011 *) %o A123266 (PARI) A007088(n)=fromdigits(binary(n),10) %o A123266 is(n)=isprime(n) && isprime(n=A007088(n)) && isprime(A007088(n)) \\ _Charles R Greathouse IV_, Apr 08 2015 %Y A123266 Cf. A065720, A007088, A256621, A256622. %K A123266 base,nonn %O A123266 1,1 %A A123266 _Martin Raab_, Oct 09 2006