A061950 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, 80, 321, 401, 1105, 1440, 2185, 17665, 26585, 132920, 287216, 659355, 1267785, 2096240, 3612505

Offset

1,2

Comments

This sequence differs from A029514 in that all least significant zeros are removed before concatenation.

No more terms < 10^7. [Lars Blomberg, Oct 24 2011]

Links

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

Index entries for related sequences

Example

See A061931 for example.

Mathematica

b = 21; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[c, IntegerDigits[IntegerReverse[#, b], b]], b], #] &] (* Robert Price, Mar 08 2020 *)

Crossrefs

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

Sequence in context: A163979 A124248 A029514 * A166093 A165785 A362057

Adjacent sequences: A061947 A061948 A061949 * A061951 A061952 A061953

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(17)-a(20) from Lars Blomberg, Oct 24 2011

Status

approved