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 A367004 #23 Oct 28 2024 09:35:47
%S A367004 3,3,5,5,7,5,3,3,11,7,13,13,3,3,17,17,5,11,3,3,23,13,5,5,3,3,7,29,31,
%T A367004 17,3,3,47,19,37,37,3,3,41,41,13,23,3,3,11,5,7,7,3,3,53,7,5591,29,3,3,
%U A367004 5,31,37,61,3,3,5,5,67,5,3,3,7,37,11,41,3,3,149
%N A367004 a(n) is the smallest prime factor of n*2^n+1.
%H A367004 Amiram Eldar, <a href="/A367004/b367004.txt">Table of n, a(n) for n = 1..914</a> (terms 1..350 from Robert Israel)
%F A367004 a(n) = A020639(A002064(n)).
%p A367004 seq(min(numtheory:-factorset(n*2^n+1)), n=1..100); # _Robert Israel_, Nov 09 2023
%t A367004 Table[FactorInteger[n 2^n+1][[1,1]],{n,80}] (* _Harvey P. Dale_, Aug 14 2024 *)
%Y A367004 Cf. A002064, A005849, A020639, A049479, A367002, A367003, A367005.
%K A367004 nonn
%O A367004 1,1
%A A367004 _Sean A. Irvine_, Oct 31 2023