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

Offset: 1

Author

Larry Reeves (larryr(AT)acm.org), May 24 2001

Keywords

• nonn
• base
• more

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

Examples

			See A061931 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 = 7; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[c, IntegerDigits[IntegerReverse[#, b], b]], b], #] &] (* Robert Price, Mar 07 2020 *)

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

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