A061947 - OEIS

A061947

Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 18 (most significant digit on right).

1, 2, 3, 6, 9, 17, 47, 61, 69, 137, 323, 385, 674, 731, 884, 1245, 1253, 17204, 35580, 37282, 73270, 74919, 78625, 98413, 119017, 263197, 313732, 402321, 467738, 661300, 4757138, 8445220, 9481937

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OFFSET

1,2

COMMENTS

This sequence differs from A029511 in that all least significant zeros are removed before concatenation.

No more terms < 10^7. - Lars Blomberg, Oct 23 2011

LINKS

Table of n, a(n) for n=1..33.

Index entries for related sequences

EXAMPLE

See A061931 for example.

MATHEMATICA

b = 18; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[c, IntegerDigits[IntegerReverse[#, b], b]], b], #] &] (* Robert Price, Mar 08 2020 *)

PROG

(PARI) lista(nn) = my(s, t); for(k=1, nn, s=k/18^valuation(k, 18); while(s, t=t*18+s%18; s\=18); 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: A374686 A095982 A095090 * A018251 A218339 A329248

Adjacent sequences: A061944 A061945 A061946 * A061948 A061949 A061950

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(29)-a(33) from Lars Blomberg, Oct 23 2011

STATUS

approved