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 A029513 #18 Mar 13 2020 10:40:26
%S A029513 1,2,4,5,6,10,12,14,18,19,53,703,1824,2185,2546,5054,6594,9841,
%T A029513 1393056,1648110,1984492,2648114,3430811,8070122
%N A029513 Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 20 (most significant digit on right).
%C A029513 This sequence differs from A061949 in that all least significant zeros are kept during concatenation.
%C A029513 No more terms < 10^7. [_Lars Blomberg_, Oct 14 2011]
%H A029513 <a href="/index/N#concat">Index entries for related sequences</a>
%e A029513 See A029495 for example.
%t A029513 b = 20; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[c, Reverse[IntegerDigits[#, b]]], b], #] &] (* _Robert Price_, Mar 13 2020 *)
%Y A029513 Cf. A029447-A029470, A029471-A029494, A029495-A029518, A029519-A029542, A061931-A061954, A061955-A061978.
%K A029513 nonn,base,more
%O A029513 1,2
%A A029513 _Olivier Gérard_
%E A029513 Edited and updated by Larry Reeves (larryr(AT)acm.org), Apr 12 2002
%E A029513 Additional comments and more terms from Larry Reeves (larryr(AT)acm.org), May 25 2001
%E A029513 a(19)-a(24) from _Lars Blomberg_, Oct 14 2011