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 A157429 #5 Feb 16 2025 08:33:09
%S A157429 20,98,114,368,494,474,194,258,264,224,374,740,740,648,322,376,398,
%T A157429 1000,1000,440,986,608,754,1000,544,644,1034,1274,406,1274,152,644,
%U A157429 1274,50,1220,484,34,804,714,440,594,1014,220,1000,1182,370,390,574
%N A157429 Lower left-hand y-coordinates of invisible 2x2 squares with 0 < x < y.
%H A157429 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/VisiblePoint.html">Visible Point</a>
%e A157429 {54, 20}, {174, 98}, {550, 114}, {574, 368}, {588, 494}, {608, 474}, ...
%Y A157429 Cf. A157426, A157427, A157428.
%K A157429 nonn
%O A157429 1,1
%A A157429 _Eric W. Weisstein_, Mar 01 2009