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 A123704 #28 Sep 06 2024 08:06:29
%S A123704 6,8,9,11,15,31,48,60,314,701,940,942,2164,2981,3810,6971,12068,13641,
%T A123704 16502,68800
%N A123704 Numbers k such that (5^p - 3^p)/2 is prime, where p = prime(k).
%C A123704 The corresponding primes p = prime(a(n)) are listed in A121877.
%C A123704 The corresponding primes of the form (5^p - 3^p)/2 are listed in A123705.
%C A123704 a(13) is greater than 1000. - _Farideh Firoozbakht_, Oct 11 2006
%F A123704 a(n) = primepi(A121877(n)).
%t A123704 Do[If[PrimeQ[(5^Prime[n] - 3^Prime[n])/2], Print[n]], {n, 1000}] (* _Robert G. Wilson v_, Jan 12 2007 *)
%t A123704 PrimePi[#]&/@Select[Prime[Range[1000]],PrimeQ[(5^#-3^#)/2]&] (* _Harvey P. Dale_, Sep 23 2018 *)
%Y A123704 Cf. A005059, A121877, A123705.
%K A123704 nonn,more
%O A123704 1,1
%A A123704 _Alexander Adamchuk_, Oct 08 2006
%E A123704 More terms from _Farideh Firoozbakht_, Oct 11 2006
%E A123704 a(13)-a(16) computed from A121877 by _Jinyuan Wang_, Mar 23 2020
%E A123704 a(17)-a(19) from _Kellen Shenton_, May 18 2022
%E A123704 a(20) from _Amiram Eldar_, Sep 06 2024