A029476 - OEIS

%I #38 May 14 2024 10:41:20

%S 1,3,15,16,29,48,75,144,477,6211,16053,32688,40431,66313,129825,

%T 134224,278064,366064,386863,3157824,4446069,6697664,8354233,28775616,

%U 33559488,34107072,38339136,50059629,50280080,71693520,113603184,220308720,247082832,2637755936

%N Numbers k that divide the (left) concatenation of all numbers <= k written in base 7 (most significant digit on left).

%C a(40) > 3*10^10. - _Jason Yuen_, May 14 2024

%H Jason Yuen, <a href="/A029476/b029476.txt">Table of n, a(n) for n = 1..39</a>

%H <a href="/index/N#concat">Index entries for related sequences</a>

%e 15 is a term: 212016151413121110654321_7 = 59785983230307066720 = 15 * 3985732215353804448.

%t b = 7; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[IntegerDigits[#, b], c], b], #] &] (* _Robert Price_, Mar 12 2020 *)

%Y Cf. A007093.

%Y Cf. A029447-A029470, A029471-A029494, A029495-A029518, A029519-A029542, A061931-A061954, A061955-A061978.

%K nonn,base

%O 1,2

%A _Olivier Gérard_

%E More terms from 6211 from Andrew Gacek (andrew(AT)dgi.net), Feb 20 2000

%E More terms from Larry Reeves (larryr(AT)acm.org), Sep 29 2001

%E Edited and updated by Larry Reeves (larryr(AT)acm.org), Apr 12 2002

%E a(20)-a(30) from _Max Alekseyev_, May 13 2011