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 A363069 #22 May 20 2023 23:16:28
%S A363069 1,1,1,2,2,3,4,4,4,4,5,5,6,6,6,7,8,8,8,8,9,9,10,10,11,11,12,12,12,13,
%T A363069 13,13,13,14,14,14,15,15,16,16,17,17,18,18,18,19,19,19,20,20,20,20,21,
%U A363069 21,22,22,23,23,24,24,25,25,25,25,26,26,26,26,26,27,27
%N A363069 Size of the largest subset of {1,2,...,n} such that no two elements sum to a perfect square.
%H A363069 Z. DeStefano, <a href="http://www.mathmasterzach.com/Math/SquarelessSets.html">Maximum Sized Sets With Sums That Avoid Squares</a>
%F A363069 The set: {k | k <= n, k == 1 (mod 3)} provides a lower bound: a(n) >= floor((n+2)/3).
%e A363069 The first few examples where a(n) increases are {1}, {1,4}, {1,4,6}, and {1,4,6,7}.
%Y A363069 Cf. A100719, A210380.
%K A363069 nonn
%O A363069 1,4
%A A363069 _Zachary DeStefano_, May 16 2023