A061978 Numbers n such that n divides the (left) concatenation of all numbers <= n written in base 25 (most significant digit on right).

1, 3, 9, 21, 33, 57, 96, 864, 1033, 1661, 6449, 6624, 10464, 68249, 81664, 108981, 164384, 167571, 234311, 2420409, 5490464

Offset

1,2

Comments

This sequence differs from A029542 in that all least significant zeros are kept during concatenation.

No more terms < 7*10^6.

Links

Table of n, a(n) for n=1..21.

Index entries for related sequences

Example

See A061955 for example.

Mathematica

b = 25; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[Reverse[IntegerDigits[#, b]], c], b], #] &] (* Robert Price, Mar 09 2020 *)

Crossrefs

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

Sequence in context: A182632 A351894 A286590 * A031886 A147458 A169927

Adjacent sequences: A061975 A061976 A061977 * A061979 A061980 A061981

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(20)-a(21) from Lars Blomberg, Jul 22 2011

Status

approved