A061934 Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 5 (most significant digit on right).

1, 16, 19, 207, 350376, 723792, 853456, 1894016

Offset

1,2

Comments

This sequence differs from A029498 in that all least significant zeros are removed before concatenation.

No more terms < 10^7. - Lars Blomberg, Oct 17 2011

Links

Table of n, a(n) for n=1..8.

Index entries for related sequences

Example

See A061931 for example.

Mathematica

cat = 0; k = 1; lst = {}; While[k < 100000, c = FromDigits@ Reverse@ IntegerDigits[k, 5]; cat = cat*10^Floor[ Log10[c] + 1] + c; If[ Mod[ FromDigits[ IntegerDigits@ cat, 5], k] == 0, AppendTo[lst, k]; Print[k]]; k++]; lst (* Robert G. Wilson v, Oct 17 2011 *)
b = 5; c = {}; Select[Range[10^4], Divisible[FromDigits[
c = Join[c, IntegerDigits[IntegerReverse[#, b], b]], b], #] &] (* Robert Price, Mar 07 2020 *)

Prog

(PARI) lista(nn, m=5) = my(s, t); for(k=1, nn, s=k/m^valuation(k, m); while(s, t=t*m+s%m; s\=m); if(t%k==0, print1(k, ", "))); \\ Jinyuan Wang, Dec 05 2020

Crossrefs

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

Sequence in context: A030402 A303813 A335210 * A195683 A199716 A163901

Adjacent sequences: A061931 A061932 A061933 * A061935 A061936 A061937

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(6)-a(8) from Lars Blomberg, Oct 17 2011

Status

approved