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A080025 Numbers n having at least one divisor d such that in binary representation d and n/d have the same number of 1's as n. 3
1, 2, 4, 8, 9, 16, 18, 32, 36, 49, 64, 72, 98, 128, 133, 144, 196, 225, 256, 259, 266, 273, 288, 385, 392, 450, 512, 518, 532, 546, 576, 585, 645, 770, 784, 897, 900, 961, 1024, 1029, 1035, 1036, 1064, 1065, 1092, 1152, 1155, 1161, 1170, 1290, 1539, 1540, 1568 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

MATHEMATICA

bn1Q[n_]:=AnyTrue[Union/@(Select[{DigitCount[#, 2, 1], DigitCount[n/#, 2, 1]}&/@ Divisors[n], #[[1]]==#[[2]]&]), #=={DigitCount[n, 2, 1]}&]; Select[Range[ 1600], bn1Q] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Aug 03 2020 *)

CROSSREFS

Cf. A007088, A000120, A000005.

Cf. A080024(a(n))>0, A080026 is a subsequence.

Sequence in context: A330710 A023898 A125853 * A152111 A316856 A324524

Adjacent sequences:  A080022 A080023 A080024 * A080026 A080027 A080028

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jan 21 2003

STATUS

approved

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Last modified December 1 01:17 EST 2021. Contains 349426 sequences. (Running on oeis4.)