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 A031189 #11 Feb 16 2025 08:32:36 %S A031189 4,37,40,55,73,124,142,157,175,178,187,214,223,232,241,256,265,268, %T A031189 286,307,322,370,400,412,421,505,517,526,550,562,571,625,628,652,682, %U A031189 703,715,718,730,751,781,817,826,862,871,1024,1042,1057,1075 %N A031189 Numbers having period-4 5-digitized sequences. %H A031189 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Digitaddition.html">Digitaddition</a> %K A031189 nonn,base %O A031189 1,1 %A A031189 _Eric W. Weisstein_