A061936 - OEIS

A061936

Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 7 (most significant digit on right).

1, 3, 12, 27, 48, 72, 79, 363, 600, 1277, 1289, 1815, 15272, 18492, 38484, 83556, 87312, 148336, 205731, 222176, 420900, 549876, 607797, 624648, 716064, 5651851

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

This sequence differs from A029500 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..26.

Index entries for related sequences

EXAMPLE

See A061931 for example.

MATHEMATICA

b = 7; 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=7) = 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: A345960 A271183 A125614 * A074630 A033428 A213486

Adjacent sequences: A061933 A061934 A061935 * A061937 A061938 A061939

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; Aug 25 2002

a(23)-a(26) from Lars Blomberg, Oct 17 2011

STATUS

approved