A061960 Numbers n such that n divides the (left) concatenation of all numbers <= n written in base 7 (most significant digit on right).

1, 3, 12, 171, 324, 717, 867, 977, 2040, 6017, 13921, 54036, 81097, 88580, 265515, 306612, 349707, 1075152, 1189787, 2579041

Offset

1,2

Comments

This sequence differs from A029524 in that all least significant zeros are kept during concatenation.

No more terms < 10^7.

Links

Table of n, a(n) for n=1..20.

Index entries for related sequences

Example

See A061955 for example.

Mathematica

b = 7; c = {}; Select[Range[10^4], Divisible[FromDigits[
c = Join[Reverse[IntegerDigits[#, b]], c], b], #] &] (* Robert Price, Mar 07 2020 *)

Crossrefs

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

Sequence in context: A356719 A004168 A301650 * A120606 A089428 A211892

Adjacent sequences: A061957 A061958 A061959 * A061961 A061962 A061963

Keyword

nonn,base,more

Author

Larry Reeves (larryr(AT)acm.org), May 24 2001

Extensions

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

a(18)-a(20) from Lars Blomberg, Aug 23 2011

Status

approved