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A061931 Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 2 (most significant digit on right). 142
1, 3, 7, 39, 63, 523, 4983, 25007, 892217, 1142775, 1381311, 1751751 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

This sequence differs from A029495 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..12.

Index entries for related sequences

EXAMPLE

1234567 -> (1)(01)(11)(001)(101)(011)(111) base 2 -> 1111110111111 base 2 = 8127 and 7 divides 8127.

CROSSREFS

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

Sequence in context: A169741 A282427 A192198 * A057203 A056250 A113870

Adjacent sequences:  A061928 A061929 A061930 * A061932 A061933 A061934

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(9)-a(12) from Lars Blomberg, Oct 17 2011

STATUS

approved

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Last modified October 20 01:25 EDT 2018. Contains 316378 sequences. (Running on oeis4.)