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Revision History for A162215

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A162215

a(n) is the smallest multiple of n that is greater than 2n and contains the same number of 1's in its binary representation as n contains.
(history; published version)

#13 by Susanna Cuyler at Sun Feb 24 21:09:23 EST 2019

STATUS

proposed

approved

#12 by Michael De Vlieger at Sun Feb 24 20:53:17 EST 2019

STATUS

editing

proposed

#11 by Michael De Vlieger at Sun Feb 24 20:53:15 EST 2019

MATHEMATICA

Array[Block[{k = 3, d = DigitCount[#, 2, 1]}, While[DigitCount[k #, 2, 1] != d, k++]; k #] &, 59] (* Michael De Vlieger, Feb 24 2019 *)

#10 by Michael De Vlieger at Sun Feb 24 20:52:55 EST 2019

LINKS

Michael De Vlieger, <a href="/A162215/b162215.txt">Table of n, a(n) for n = 1..10000</a>

STATUS

proposed

editing

#9 by Jon E. Schoenfield at Sun Feb 24 20:39:02 EST 2019

STATUS

editing

proposed

#8 by Jon E. Schoenfield at Sun Feb 24 20:38:58 EST 2019

NAME

a(n) = is the smallest multiple of n that is > greater than 2n and contains the same number of 1's in its binary representation as n contains.

MAPLE

A000120 := proc(n) add(d, d=convert(n, base, 2)) ; end: A162215 := proc(n) local k; for k from 3 do if A000120(k*n)= A000120(n) then RETURN(k*n) ; fi; od: end: seq(A162215(n), n=1..80) ; [From _# _R. J. Mathar_, Jul 04 2009]

CROSSREFS

Cf. A077459.

STATUS

approved

editing

#7 by Charles R Greathouse IV at Tue Mar 11 01:32:34 EDT 2014

AUTHOR

__Leroy Quet__, , Jun 28 2009

Discussion

Tue Mar 11

01:32

OEIS Server: https://oeis.org/edit/global/2122

#6 by N. J. A. Sloane at Wed Feb 05 20:18:58 EST 2014

AUTHOR

__Leroy Quet_, _, Jun 28 2009

Discussion

Wed Feb 05

20:18

OEIS Server: https://oeis.org/edit/global/2118

#5 by N. J. A. Sloane at Wed Feb 05 20:12:03 EST 2014

AUTHOR

_Leroy Quet, _, Jun 28 2009

Discussion

Wed Feb 05

20:12

OEIS Server: https://oeis.org/edit/global/2117

#4 by Russ Cox at Fri Mar 30 17:40:01 EDT 2012

MAPLE

EXTENSIONS

a(4) corrected and sequence extended by _R. J. Mathar (mathar(AT)strw.leidenuniv.nl), _, Jul 04 2009

Discussion

Fri Mar 30

17:40

OEIS Server: https://oeis.org/edit/global/190