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 A248528 #12 Sep 08 2022 08:46:10
%S A248528 4,30,64,106,140,166,234,276,310,336,344,370,404,446,480,506,514,540,
%T A248528 574,650,676,744,786,820,846,854,880,914,956,990,1016,1024,1050,1160,
%U A248528 1186,1194,1220,1254,1296,1330,1356,1364,1390,1424,1466,1534,1560,1636,1670
%N A248528 Numbers n such that the smallest prime divisor of n^2+1 is 17.
%C A248528 Or numbers n such that the smallest prime divisor of n^2+1 is A002313(4).
%C A248528 a(n)== 4 or 30 (mod 34).
%H A248528 Amiram Eldar, <a href="/A248528/b248528.txt">Table of n, a(n) for n = 1..10000</a>
%e A248528 30 is in the sequence because 30^2+1= 17*53.
%t A248528 lst={};Do[If[FactorInteger[n^2+1][[1, 1]]==17, AppendTo[lst, n]], {n, 2, 2000}]; lst
%t A248528 p = 17; ps = Select[Range[p - 1], Mod[#, 4] != 3 && PrimeQ[#] &]; Select[Range[1670], Divisible[(nn = #^2 + 1), p] && ! Or @@ Divisible[nn, ps] &] (* _Amiram Eldar_, Aug 16 2019 *)
%o A248528 (Magma) [n: n in [2..2000] | PrimeDivisors(n^2+1)[1] eq 17]; // _Bruno Berselli_, Oct 08 2014
%Y A248528 Cf. A089120, A002313, A248527.
%K A248528 nonn,easy
%O A248528 1,1
%A A248528 _Michel Lagneau_, Oct 08 2014