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 A080443 #17 Sep 08 2022 08:45:09
%S A080443 3,5,11,29,83,7,43,199,6563,127,59051,25307,48313,63773,4782971,
%T A080443 14348909,119243,335429,23203,10613,60089,1224149,795323,919,
%U A080443 282429536483,1583717027,2541865828331,693236134999,174632003473
%N A080443 Largest prime factor of 3^n+2.
%H A080443 Hugo Pfoertner, <a href="/A080443/b080443.txt">Table of n, a(n) for n = 0..210 (first 100 terms from Harvey P. Dale)</a>
%t A080443 Table[FactorInteger[3^n+2][[-1,1]],{n,0,30}] (* _Harvey P. Dale_, Oct 21 2011 *)
%o A080443 (PARI) for(n=0,28,f=factor(3^n+2);print1(f[#f[,1],1],", ")) \\ _Hugo Pfoertner_, Jul 12 2019
%o A080443 (Magma) [Max(PrimeDivisors(3^n+2)):n in [0..28]]; // _Marius A. Burtea_, Jul 12 2019
%Y A080443 Cf. A051783, A057735, A080798, A081715.
%K A080443 nonn
%O A080443 0,1
%A A080443 _Hugo Pfoertner_, Mar 21 2003
%E A080443 Corrected by _T. D. Noe_, Nov 15 2006