A029476 Numbers k that divide the (left) concatenation of all numbers <= k written in base 7 (most significant digit on left).

1, 3, 15, 16, 29, 48, 75, 144, 477, 6211, 16053, 32688, 40431, 66313, 129825, 134224, 278064, 366064, 386863, 3157824, 4446069, 6697664, 8354233, 28775616, 33559488, 34107072, 38339136, 50059629, 50280080, 71693520, 113603184, 220308720, 247082832, 2637755936

Offset: 1

Author

Olivier Gérard

Keywords

• nonn
• base

Comments

a(40) > 3*10^10. - Jason Yuen, May 14 2024

Examples

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

Links

• Jason Yuen, Table of n, a(n) for n = 1..39
• Index entries for related sequences

Crossrefs

Cf. A007093.

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

Programs

Mathematica

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

Extensions

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

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

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

a(20)-a(30) from Max Alekseyev, May 13 2011