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 A277122 #15 Aug 11 2024 04:58:36
%S A277122 7,151,1972807,1818989407598411628849054391,
%T A277122 21382117680737565169124291737211855035830505403680318251383549467509816267540836044857784735512271804718726595516967
%N A277122 Primes of the form 5^k + 3^k - 1.
%C A277122 The sequence of corresponding k starts: 1, 3, 9, 39, 165 (A180741).
%C A277122 Primes in A155603. - _Altug Alkan_, Oct 01 2016
%F A277122 a(n) = A155603(A180741(n)). - _Amiram Eldar_, Aug 11 2024
%t A277122 Select[Table[5^k + 3^k - 1, {k, 0, 200}], PrimeQ] (* _Amiram Eldar_, Aug 11 2024 *)
%o A277122 (PARI) lista(kmax) = {my(p); for(k = 0, kmax, p = 5^k + 3^k - 1; if(isprime(p), print1(p, ", ")));} \\ _Amiram Eldar_, Aug 11 2024
%Y A277122 Cf. A000040, A081508, A155603, A180741.
%K A277122 nonn
%O A277122 1,1
%A A277122 _Alex Ratushnyak_, Sep 30 2016