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 A291861 #10 Jun 17 2025 09:23:19
%S A291861 43,337,117643,40353601,558545864083284001,1341068619663964900801,
%T A291861 7730993719707444524137094401,
%U A291861 256923577521058878088611477224235621321601,4318114567396436564035293097707728087552248843
%N A291861 Prime numbers of the form 7^k - 6.
%H A291861 Robert Price, <a href="/A291861/b291861.txt">Table of n, a(n) for n = 1..10</a>
%H A291861 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 A291861 Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop">PRP Records</a>
%H A291861 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>
%t A291861 Select[Table[7^k - 6, {k, 1, 100}], PrimeQ[#] &]
%Y A291861 Cf. A191469.
%K A291861 nonn
%O A291861 1,1
%A A291861 _Robert Price_, Sep 04 2017