The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A145254 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A145254

a(n) = the smallest positive integer that is non-coprime to n and has the same number of 1's in its binary representation as n.
(history; published version)

#13 by Alois P. Heinz at Fri Oct 27 20:52:08 EDT 2017

STATUS

editing

approved

#12 by Alois P. Heinz at Fri Oct 27 20:52:06 EDT 2017

KEYWORD

base,nonn,look,changed

STATUS

approved

editing

#11 by Alois P. Heinz at Fri Oct 27 20:51:30 EDT 2017

STATUS

proposed

approved

#10 by Michel Marcus at Fri Oct 27 02:04:22 EDT 2017

STATUS

editing

proposed

#9 by Michel Marcus at Fri Oct 27 02:01:32 EDT 2017

PROG

(PARI) a(n) = {my(k = 1, hn = hammingweight(n)); while ((hammingweight(k) != hn) || (gcd(n, k) == 1), k++); k; } \\ Michel Marcus, Oct 27 2017

STATUS

proposed

editing

#8 by Michael De Vlieger at Thu Oct 26 21:06:17 EDT 2017

STATUS

editing

proposed

#7 by Michael De Vlieger at Thu Oct 26 21:06:15 EDT 2017

CROSSREFS

Cf. A145255, A145256, A145257.

#6 by Michael De Vlieger at Thu Oct 26 21:06:00 EDT 2017

LINKS

Michael De Vlieger, <a href="/A145254/b145254.txt">Table of n, a(n) for n = 2..16384</a>

MATHEMATICA

Table[Function[k, SelectFirst[Range[2, n], And[! CoprimeQ[#, n], DigitCount[#, 2, 1] == k] &]]@ DigitCount[n, 2, 1], {n, 2, 83}] (* Michael De Vlieger, Oct 26 2017 *)

STATUS

approved

editing

#5 by Charles R Greathouse IV at Wed Apr 09 10:16:33 EDT 2014

AUTHOR

Leroy Quet , Oct 05 2008

Discussion

Wed Apr 09

10:16

OEIS Server: https://oeis.org/edit/global/2154

#4 by N. J. A. Sloane at Wed Feb 05 20:18:50 EST 2014

AUTHOR

_Leroy Quet _ Oct 05 2008

Discussion

Wed Feb 05

20:18

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