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 A248531 #13 Sep 08 2022 08:46:10
%S A248531 50,114,196,214,296,624,706,770,870,934,1034,1180,1280,1426,1444,1590,
%T A248531 1690,1754,1836,1936,2000,2164,2246,2264,2346,2574,2674,2756,2820,
%U A248531 2984,3066,3084,3230,3330,3394,3494,3576,3640,3740,3886,3904,4214,4296,4460,4624
%N A248531 Numbers n such that the smallest prime divisor of n^2+1 is 41.
%C A248531 Or numbers n such that the smallest prime divisor of n^2+1 is A002313(7).
%C A248531 a(n)== 32 or 50 (mod 82).
%H A248531 Amiram Eldar, <a href="/A248531/b248531.txt">Table of n, a(n) for n = 1..10000</a>
%e A248531 50 is in the sequence because 50^2+1= 41*61.
%t A248531 lst={};Do[If[FactorInteger[n^2+1][[1, 1]]==41, AppendTo[lst, n]], {n, 2, 2000}]; lst
%t A248531 Select[Range[5000],FactorInteger[#^2+1][[1,1]]==41&] (* _Harvey P. Dale_, Aug 15 2017 *)
%t A248531 p = 41; ps = Select[Range[p - 1], Mod[#, 4] != 3 && PrimeQ[#] &]; Select[Range[5000], Divisible[(nn = #^2 + 1), p] && ! Or @@ Divisible[nn, ps] &] (* _Amiram Eldar_, Aug 16 2019 *)
%o A248531 (Magma) [n: n in [2..5000] | PrimeDivisors(n^2+1)[1] eq 41]; // _Bruno Berselli_, Oct 08 2014
%Y A248531 Cf. A089120, A002313, A209874, A248527, A248528, A248529, A248530.
%K A248531 nonn,easy
%O A248531 1,1
%A A248531 _Michel Lagneau_, Oct 08 2014