A029514 Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 21 (most significant digit on right).

1, 3, 5, 7, 15, 25, 55, 80, 143, 187, 192, 387, 1385, 1760, 4080, 9040, 9245, 15565, 17776, 20080, 28400, 30019, 30063, 37312, 38368, 52217, 56277, 84480, 97504, 123040, 293045, 458560, 1258528, 2437600, 2442000, 3122240, 7216880

Offset

1,2

Comments

This sequence differs from A061950 in that all least significant zeros are kept during concatenation.

No more terms < 10^7. [Lars Blomberg, Oct 11 2011]

Links

Table of n, a(n) for n=1..37.

Index entries for related sequences

Example

See A029495 for example.

Mathematica

b = 21; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[c, Reverse[IntegerDigits[#, b]]], b], #] &] (* Robert Price, Mar 13 2020 *)

Crossrefs

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

Sequence in context: A172235 A163979 A124248 * A061950 A166093 A165785

Adjacent sequences: A029511 A029512 A029513 * A029515 A029516 A029517

Keyword

nonn,base

Author

Olivier Gérard

Extensions

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

Additional comments and more terms from Larry Reeves (larryr(AT)acm.org), May 25 2001

a(32)-a(37) from Lars Blomberg, Oct 11 2011

Status

approved