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 A029542 #30 Jan 13 2025 13:25:25
%S A029542 1,3,9,21,27,48,144,352,361,4672,5904,7392,15323,25488,32096,55491,
%T A029542 71712,89259,101437,139776,752011,2215168,5082544,6766761
%N A029542 Numbers k such that k divides the (left) concatenation of all numbers <= k written in base 25 (most significant digit on right and removing all least significant zeros before concatenation).
%C A029542 This sequence differs from A061978 in that all least significant zeros are removed before concatenation.
%C A029542 No more terms < 10^7. - _Lars Blomberg_, Oct 01 2011
%H A029542 <a href="/index/N#concat">Index entries for related sequences</a>
%e A029542 See A029519 for example.
%t A029542 b = 25; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[IntegerDigits[ IntegerReverse[ #, b], b], c], b], #] &] (* _Robert Price_, Mar 13 2020 *)
%Y A029542 Cf. A029447-A029470, A029471-A029494, A029495-A029518, A029519-A029542, A061931-A061954, A061955-A061978.
%K A029542 nonn,base,more
%O A029542 1,2
%A A029542 _Olivier Gérard_
%E A029542 Edited and updated by Larry Reeves (larryr(AT)acm.org), Apr 12 2002
%E A029542 Additional comments and more terms from Larry Reeves (larryr(AT)acm.org), Jun 04 2001
%E A029542 a(21)-a(24) from _Lars Blomberg_, Oct 01 2011