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 A061970 #14 Mar 09 2020 21:59:52
%S A061970 1,25,64,67,1477,118531,421353,573333,799155
%N A061970 Numbers n such that n divides the (left) concatenation of all numbers <= n written in base 17 (most significant digit on right).
%C A061970 This sequence differs from A029534 in that all least significant zeros are kept during concatenation.
%C A061970 No more terms < 8*10^6.
%H A061970 <a href="/index/N#concat">Index entries for related sequences</a>
%e A061970 See A061955 for example.
%t A061970 b = 17; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[Reverse[IntegerDigits[#, b]], c], b], #] &] (* _Robert Price_, Mar 09 2020 *)
%Y A061970 Cf. A029447-A029470, A029471-A029494, A029495-A029518, A029519-A029542, A061931-A061954, A061955-A061978.
%K A061970 nonn,base,more
%O A061970 1,2
%A A061970 Larry Reeves (larryr(AT)acm.org), May 24 2001
%E A061970 Edited and updated by Larry Reeves (larryr(AT)acm.org), Apr 12 2002; Aug 25, 2002
%E A061970 a(9) from _Lars Blomberg_, Aug 04 2011