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 A367005 #15 Oct 28 2024 09:35:43 %S A367005 1,3,3,5,13,23,11,23,683,419,19,1733,199,11833,487,997,61681,4691,211, %T A367005 5279,7541,1914791,7177,607,5233,6689,2373919,336823,8937209,6051013, %U A367005 409,11681,25781083,6031230671,18803,32502455213,934861,339016085231,55586743 %N A367005 a(n) is the largest prime factor of n*2^n+1 for n>0, and a(0)=1. %H A367005 Amiram Eldar, <a href="/A367005/b367005.txt">Table of n, a(n) for n = 0..865</a> %F A367005 a(n) = A006530(A002064(n)). %t A367005 A367005[n_]:=FactorInteger[n*2^n+1][[-1,1]];Array[A367005,50,0] (* _Paolo Xausa_, Nov 09 2023 *) %Y A367005 Cf. A002064, A006530, A005420, A367003, A367004. %K A367005 nonn %O A367005 0,2 %A A367005 _Sean A. Irvine_, Oct 31 2023 %E A367005 Name edited by _Michel Marcus_, Nov 10 2023