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 A348577 #6 Nov 10 2021 17:36:03
%S A348577 1,2,3,4,5,6,7,8,9,10,11,13,14,15,16,17,18,19,20,21,22,23,25,26,27,28,
%T A348577 29,31,32,33,34,35,37,38,39,41,42,43,44,45,46,47,49,50,51,52,53,54,55,
%U A348577 57,58,59,61,62,63,64,65,66,67,68,69,71,73,74,75,76,77,78,79,81,82,83,85
%N A348577 Positive integers that are not the perimeter of any integer-sided right triangle.
%C A348577 Complement of A010814.
%t A348577 seq[max_] := Module[{s = {}, a, b, c}, Do[If[IntegerQ[c = Sqrt[a^2 + b^2]], AppendTo[s, a + b + c]], {a, max}, {b, Floor@Sqrt[a], a}]; Complement[Range[max], s]]; seq[100] (* _Amiram Eldar_, Oct 24 2021 *)
%Y A348577 Cf. A010814.
%K A348577 nonn
%O A348577 1,2
%A A348577 _Wesley Ivan Hurt_, Oct 23 2021