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 A253058 #18 Jan 23 2025 13:55:17 %S A253058 2102222,11102222,12022222,120022222,202022221,1200022222,2002022221, %T A253058 2020022221,12000022222,20200022221,202000022221 %N A253058 Complete list of numbers that take three steps to collapse to a single digit in base 3 (written in base 3). %H A253058 Steve Butler, R. L. Graham, and Richard Stong, <a href="http://www.math.ucsd.edu/~ronspubs/mis_17_bases.pdf">Collapsing numbers in bases 2, 3, and beyond</a>, in Gathering for Gardner 10, 2014. %Y A253058 Cf. A253057. %K A253058 nonn,fini,full %O A253058 1,1 %A A253058 _N. J. A. Sloane_, Jan 13 2015