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 A369391 #12 Jan 22 2024 19:27:06
%S A369391 1,1,1,2,4,10,20,26,31,35,41,63,143,399,1083,2554,5078,8596,12772,
%T A369391 17222,21792,27126,36538,62530,146701,412191,1178071,3156949,7703823,
%U A369391 16992539,33946851,61840501,103674983,161604395,236759149,330078718,446073360,606337592
%N A369391 Number of nonempty subsets of {1..n} whose elements have a square average.
%H A369391 Alois P. Heinz, <a href="/A369391/b369391.txt">Table of n, a(n) for n = 1..200</a>
%e A369391 a(5) = 4 subsets: {1}, {4}, {3, 5} and {3, 4, 5}.
%Y A369391 Cf. A051293, A126024, A309160, A339454, A357355.
%K A369391 nonn
%O A369391 1,4
%A A369391 _Ilya Gutkovskiy_, Jan 22 2024
%E A369391 a(24)-a(38) from _Alois P. Heinz_, Jan 22 2024