A029538 Numbers n such that n divides the (left) concatenation of all numbers <= n written in base 21 (most significant digit on right and removing all least significant zeros before concatenation).

1, 5, 40, 65, 80, 928, 1504, 4568, 4640, 4880, 5065, 11201, 31145, 40555, 89480, 812645, 1281320

Offset: 1

Author

Olivier Gérard

Keywords

• nonn
• base
• more

Comments

This sequence differs from A061974 in that all least significant zeros are removed before concatenation.

No more terms < 10^7. [Lars Blomberg, Sep 26 2011]

Examples

			See A029519 for example.
		

Links

• Index entries for related sequences

Crossrefs

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

Programs

Mathematica

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

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(16)-a(17) from Lars Blomberg, Sep 26 2011