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A324649 Numbers k such that A318458(k) (bitwise-AND of k and sigma(k)-k) is equal to k. 7
6, 20, 28, 36, 66, 72, 88, 100, 104, 114, 132, 150, 240, 258, 264, 272, 280, 304, 354, 368, 392, 402, 464, 496, 498, 516, 550, 552, 642, 644, 680, 708, 748, 770, 774, 784, 786, 834, 836, 840, 860, 978, 1026, 1032, 1040, 1044, 1056, 1062, 1064, 1068, 1074, 1092, 1104, 1120, 1184, 1232, 1266, 1312, 1362, 1376, 1410, 1504 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Positions of zeros in A324648. Fixed points of A318458, also positions of the records in the latter.

Intersection with A324652 gives A324643.

The odd terms are: 7425, 76545, 92565, ... (A324897).

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..20000

Index entries for sequences related to binary expansion of n

Index entries for sequences related to sigma(n)

MATHEMATICA

Select[Range@ 1600, BitAnd[#, DivisorSigma[1, #] - #] == # &] (* Michael De Vlieger, Apr 21 2019, after Vincenzo Librandi at A318458 *)

PROG

(PARI) for(n=1, oo, if(bitand(n, sigma(n)-n)==n, print1(n, ", ")));

CROSSREFS

Cf. A318458, A324648, A324652.

Cf. A000396, A324643, A324897, A324898 (subsequences).

Sequence in context: A345910 A316291 A090502 * A324643 A119425 A342669

Adjacent sequences:  A324646 A324647 A324648 * A324650 A324651 A324652

KEYWORD

nonn,changed

AUTHOR

Antti Karttunen, Mar 14 2019

STATUS

approved

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Last modified July 26 11:27 EDT 2021. Contains 346294 sequences. (Running on oeis4.)