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 A289724 #15 Jun 17 2025 00:37:12
%S A289724 5,59,19661,1594301,22876792454939,2954312706550833698621,
%T A289724 8862938119652501095907,
%U A289724 6170365191715177779482467945369860501784408913594010934644126825341528124785676079587659
%N A289724 Primes of the form 3^k - 22.
%H A289724 Robert Price, <a href="/A289724/b289724.txt">Table of n, a(n) for n = 1..9</a>
%H A289724 F. Firoozbakht and M. F. Hasler, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL13/Hasler/hasler2.html">Variations on Euclid's formula for Perfect Numbers</a>, JIS 13 (2010) #10.3.1.
%H A289724 Henri and Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop">PRP Records</a>
%H A289724 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>
%F A289724 a(n) = 3^A219043(n) - 22. - _Elmo R. Oliveira_, Nov 12 2023
%t A289724 Select[Table[3^k - 22, {k, 3, 100}], PrimeQ[#] &]
%Y A289724 Cf. A000040, A219043 (corresponding k's).
%K A289724 nonn
%O A289724 1,1
%A A289724 _Robert Price_, Sep 02 2017