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 A335962 #10 Jul 02 2020 03:52:16
%S A335962 1,2,3,6,8,9,10,11,12,15,16,17,20,21,25,26,27,28,29,30,33,34,35,36,37,
%T A335962 39,42,44,45,46,47,48,51,52,53,54,55,56,60,61,62,64,65,66,69,72,73,74,
%U A335962 75,78,79,80,81,83,84,87,88,89,90,91,92,96,97,98,100,101
%N A335962 Numbers k such that k^2 + 1 and k^2 + 2 are both squarefree.
%C A335962 Dimitrov (2020) proved that this sequence is infinite and has an asymptotic density Product_{p prime > 2} (1 - ((-1/p) + (-2/p) + 2)/p^2) = 0.67187..., where (a/p) is the Legendre symbol.
%H A335962 Amiram Eldar, <a href="/A335962/b335962.txt">Table of n, a(n) for n = 1..10000</a>
%H A335962 S. I. Dimitrov, <a href="https://arxiv.org/abs/2004.09975">Pairs of square-free values of the type n^2+1, n^2+2</a>, arXiv:2004.09975 [math.NT], 2020.
%e A335962 1 is a term since 1^2 + 1 = 2 and 1^1 + 2 = 3 are both squarefree.
%t A335962 Select[Range[100], And @@ SquareFreeQ /@ (#^2 + {1, 2}) &]
%Y A335962 Subsequence of A049533.
%Y A335962 Cf. A005117, A007674, A069987.
%K A335962 nonn
%O A335962 1,2
%A A335962 _Amiram Eldar_, Jul 01 2020