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 A334249 #41 May 15 2020 12:24:21 %S A334249 11,88,101,448,673,776,1001,2879,3553,9537,10001,14651,36559,49056, %T A334249 51073,54116,59600,100001,505025,998999,1000001,4115964,5050250, %U A334249 5133355,10000001,10050125,19349727,26550976,33726078,35792647,42349456,43605459,50050025,66952741,88027284,88819024,100000001,105124922 %N A334249 Numbers k such that (k - digitsum(k))(k + digitsum(k)) contains k as a substring. %C A334249 All numbers of the form 10^n + 1 (for n > 0) are in the sequence. %H A334249 Giovanni Resta, <a href="/A334249/b334249.txt">Table of n, a(n) for n = 1..95</a> %e A334249 11 is a term as digitsum(11) = 2 and (11 - 2)(11 + 2) = 117, which contains '11' as a substring. %e A334249 9537 is a term as digitsum(9537) = 24 and (9537 - 24)(9537 + 24) = 90953793, which contains '9537' as a substring. %Y A334249 Cf. A007953, A257784, A125526, A082208, A225780. %K A334249 nonn,base,less %O A334249 1,1 %A A334249 _Scott R. Shannon_, May 05 2020