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 A337429 #20 Mar 30 2023 02:32:20 %S A337429 2,7,29,19,641,41,541,1597,22993,397,5521,303293,380881,25117, %T A337429 210466621,508771,1573071713,108991369171,1343341,2724783836059, %U A337429 39558401,2525293,4807441,215038823,1173553,61001,16463734208221,3813697527769,58116853330557841,327866809,99901 %N A337429 a(n) is the largest prime factor of 2^n + 5^n. %H A337429 Amiram Eldar, <a href="/A337429/b337429.txt">Table of n, a(n) for n = 0..387</a> (terms 0..200 from Hugo Pfoertner) %F A337429 a(n) = A006530(A074600(n)). %t A337429 a[n_] := FactorInteger[2^n + 5^n][[-1, 1]]; Array[a, 31, 0] (* _Amiram Eldar_, Mar 30 2023 *) %o A337429 (PARI) for(n=0,30,my(p=2^n+5^n);print1(vecmax(factor(p)[,1]),", ")) %Y A337429 Cf. A006530, A074600, A094474, A094475, A122118. %K A337429 nonn %O A337429 0,1 %A A337429 _Hugo Pfoertner_, Sep 23 2020