Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #22 Jul 26 2021 01:47:14
%S 1,3,5,9,15,19,21,43,57,255,345,385,505,1131,1395,1585,7205,11565,
%T 38949,270425,684555,8311925
%N Numbers k such that k divides the (left) concatenation of all numbers <= k written in base 16 (most significant digit on right).
%C This sequence differs from A061969 in that all least significant zeros are removed before concatenation.
%C No more terms < 10^7. [_Lars Blomberg_, Sep 20 2011]
%H <a href="/index/N#concat">Index entries for related sequences</a>
%e See A029519 for example.
%t b = 16; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[IntegerDigits[IntegerReverse[#, b], b], c], b], #] &] (* _Robert Price_, Mar 13 2020 *)
%Y Cf. A029447-A029470, A029471-A029494, A029495-A029518, A029519-A029542, A061931-A061954, A061955-A061978.
%K nonn,base,more
%O 1,2
%A _Olivier Gérard_
%E Edited and updated by Larry Reeves (larryr(AT)acm.org), Apr 12 2002
%E Additional comments and more terms from Larry Reeves (larryr(AT)acm.org), Jun 04 2001
%E a(21)-a(22) from _Lars Blomberg_, Sep 20 2011