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

1,2

Comments

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

Links

Jason Yuen, Table of n, a(n) for n = 1..39

Index entries for related sequences

Example

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

Mathematica

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

Crossrefs

Cf. A007093.

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

Sequence in context: A332961 A012634 A043060 * A154317 A291122 A323033

Adjacent sequences: A029473 A029474 A029475 * A029477 A029478 A029479

Keyword

nonn,base

Author

Olivier Gérard

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

Status

approved