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 A113797 #14 Jul 27 2021 07:36:18
%S A113797 48,100,147,3468,10000,10101,13467,16128,34188,140400,190476,216513,
%T A113797 300625,334668,416768,484848,530901,1000000,1010100,1016127,1034187,
%U A113797 1140399,1190475,1216512,1300624,1334667,1416767,1484847,1530900
%N A113797 Numbers k whose digits can be divided into two contiguous parts, k = concatenate(x, y), such that k = |x^2 - y^2|.
%e A113797 3468 = |34^2 - 68^2|.
%t A113797 lst = {}; Do[p = 10; While[n > p, If[Abs[Mod[n, p]^2 - Floor[n/p]^2] == n, AppendTo[lst, n]]; p*=10], {n, 10^6}]; lst
%K A113797 base,nonn
%O A113797 1,1
%A A113797 _Giovanni Resta_, Jan 21 2006