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 A105768 #8 Feb 16 2025 08:32:57
%S A105768 3,7,31,127,983,122401,15231991,30341581,60439343,239818559,
%T A105768 235883775871,935968272887,462162688688737,3592979567873032703,
%U A105768 439785318101603999198591,432569613524779275706080077
%N A105768 Prime Lucas 7-step numbers, A104621.
%H A105768 Tony D. Noe and Jonathan Vos Post, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL8/Noe/noe5.html">Primes in Fibonacci n-step and Lucas n-step Sequences,</a> J. of Integer Sequences, Vol. 8 (2005), Article 05.4.4
%H A105768 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Lucasn-StepNumber.html">Lucas n-Step Number</a>
%t A105768 a={-1, -1, -1, -1, -1, -1, 7}; lst={}; Do[s=Plus@@a; a=RotateLeft[a]; a[[ -1]]=s; If[PrimeQ[s], AppendTo[lst, s]], {n, 1000}]; lst
%Y A105768 Cf. A104622 (indices of prime Lucas 7-step numbers).
%K A105768 nonn
%O A105768 1,1
%A A105768 _T. D. Noe_, Apr 22 2005