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 A361335 #14 Apr 03 2023 02:31:50
%S A361335 0,10,11,101,1001,111,1110,10101,10111,1111,11110,102222,101111,
%T A361335 1001111,11111,111110,1022222,1011111,10011111,11101111,111111,
%U A361335 1111110,10222222,10111111,100111111,111111212,110111111,1111111,11111110,102222222,101111111,1001111111,1111111212,1101111111,10101111111,11111111,111111110
%N A361335 Smallest decimal number containing n palindromic substrings (Version 1). See Comments for precise definition.
%C A361335 Suppose m has decimal expansion d_1 d_2 ... d_k. A palindromic substring here is any substring d_i, d_{i+1}, ..., d_j with 1 <= i <= j <= n which is palindromic, except that if d_i = 0 then i = j. For example, if m = 10^3 + 1 = 1001 there are five substrings: 1, 0, 0, 1, 1001 (but not 00). See A361336 for Version 2.
%H A361335 Giovanni Resta, <a href="/A361335/b361335.txt">Table of n, a(n) for n = 1..99</a>
%Y A361335 Cf. A361336.
%K A361335 nonn,base
%O A361335 1,2
%A A361335 _N. J. A. Sloane_, Apr 01 2023, based on postings to the Sequence Fans Mailing list by _Eric Angelini_, Mar 28 2023 (definition), and _Giovanni Resta_, Mar 28 2023 (terms)