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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
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).
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. A000396, A324643, A324897, A324898 (subsequences).
Sequence in context: A345910 A316291 A090502 * A324643 A119425 A342669
KEYWORD
nonn
AUTHOR
Antti Karttunen, Mar 14 2019
STATUS
approved