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 A366523 #12 Jan 04 2024 19:06:04
%S A366523 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,4,1,1,1,4,1,1,1,4,1,1,1,4,1,1,1,4,1,1,
%T A366523 1,4,1,1,1,4,1,1,1,4,1,1,1,4,1,1,1,4,1,1,1,4,1,1,1,4,1,1,1,4,1,1,1,4,
%U A366523 1,1,1,4,1,1,1,4,1,1,1,4,9,1,1,4,1,1,1,4,1,9,1,4,1,1,1,4,1,1,9,4
%N A366523 Largest square divisor of n which is <= sqrt(n).
%H A366523 Andrew Howroyd, <a href="/A366523/b366523.txt">Table of n, a(n) for n = 1..10000</a>
%t A366523 Table[Last[Select[Divisors[n], # <= Sqrt[n] && IntegerQ[Sqrt[#]] &]], {n, 100}]
%o A366523 (PARI) a(n) = {my(m=1); fordiv(sqrtint(n/core(n)), d, if(d^4 <= n, m=max(m,d))); m^2} \\ _Andrew Howroyd_, Oct 11 2023
%Y A366523 Cf. A008833, A033676, A366524.
%K A366523 nonn
%O A366523 1,16
%A A366523 _Ilya Gutkovskiy_, Oct 11 2023