

A029495


Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 2 (most significant digit on right).


141




OFFSET

1,2


COMMENTS

This sequence differs from A061931 in that all least significant zeros are kept during concatenation.
No more terms < 10^7. [Lars Blomberg, Oct 01 2011]


LINKS

Table of n, a(n) for n=1..3.
Index entries for related sequences


EXAMPLE

12345 > (1)(01)(11)(001)(101) base 2 > 10111001101 base 2 = 1485 and 5 divides 1485.


PROG

(PARI) is(n) = my(t=[]); for(k=1, n, t=concat(t, Vecrev(binary(k)))); if(Mod(subst(Pol(t), x, 2), n)==0, return(1), return(0)) \\ Felix Fröhlich, Jul 06 2017


CROSSREFS

Cf. A029447A029470, A029471A029494, A029495A029518, A029519A029542, A061931A061954, A061955A061978.
Sequence in context: A316446 A316128 A317434 * A086900 A200002 A265921
Adjacent sequences: A029492 A029493 A029494 * A029496 A029497 A029498


KEYWORD

nonn,base,bref


AUTHOR

Olivier Gérard


EXTENSIONS

Edited and updated by Larry Reeves (larryr(AT)acm.org), Apr 12 2002
Additional comments, more terms and example from Larry Reeves (larryr(AT)acm.org), May 25 2001


STATUS

approved



