

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
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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.


MATHEMATICA

b = 2; c = {}; Select[Range[10^4], Divisible[FromDigits[
c = Join[c, IntegerDigits[IntegerReverse[#, b], b]], b], #] &] (* Robert Price, Mar 07 2020 *)


CROSSREFS

Cf. A029447A029470, A029471A029494, A029495A029518, A029519A029542, A061931A061954, A061955A061978.
Sequence in context: A335812 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



