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 A116238 #9 Jul 18 2021 02:47:59 %S A116238 69,79822842,69852478553064869297984899963804, %T A116238 77473062193002372448027740546436,77747359197583788609974143907616, %U A116238 84341826458653210947638195982112,85367942837521291760016984490248 %N A116238 Numbers k such that k*(k+7) gives the concatenation of two numbers m and m-8. %e A116238 79822842 * 79822849 = 63716866//63716858, where // denotes concatenation. %Y A116238 Cf. A116107, A116230, A116237, A116239, A116243. %K A116238 nonn,base %O A116238 1,1 %A A116238 _Giovanni Resta_, Feb 06 2006