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 A116296 #7 Jul 18 2021 02:55:38 %S A116296 82,77394228,89158934,36623663376237623663376336, %T A116296 37633762366336633762366236,62366237633663366237633762, %U A116296 63376336623762376336623662,86194223018927804587702129 %N A116296 Numbers k such that k*(k+3) gives the concatenation of two numbers m and m+1. %e A116296 89158934 * 89158937 = 79493157//79493158, where // denotes concatenation. %Y A116296 Cf. A116099, A116287, A116295, A116297, A116302. %K A116296 nonn,base %O A116296 1,1 %A A116296 _Giovanni Resta_, Feb 06 2006