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A100290 Numbers divisible by smallest number with same number of 1's in its binary expansion. That is, A038573(a(n)) divides a(n). 3
1, 2, 3, 4, 6, 7, 8, 9, 12, 14, 15, 16, 18, 21, 24, 28, 30, 31, 32, 33, 35, 36, 42, 45, 48, 49, 56, 60, 62, 63, 64, 66, 70, 72, 75, 84, 90, 93, 96, 98, 105, 112, 120, 124, 126, 127, 128, 129, 132, 133, 135, 140, 144, 150, 155, 161, 165, 168, 180, 186, 189, 192, 195, 196 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Contains m*(2^k-1) for 1 <= m <= 2^k + 2 and any k >= 1. - Robert Israel, Aug 04 2016

LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000

Rémy Sigrist, Scatterplot of the first 10000 terms of the first difference of A100290 (cf. A292777)

EXAMPLE

21 is a member since 21 = 10101 base 2, which is divisible by 7 = 111 base 2.

MAPLE

filter:= n -> evalb(n mod (2^numboccur(1, convert(n, base, 2))-1) = 0):

select(filter, [$1..1000]); # Robert Israel, Aug 04 2016

MATHEMATICA

Select[Range[200], Divisible[#, 2^DigitCount[#, 2, 1] - 1] &] (* Ivan Neretin, Aug 03 2016 *)

PROG

(PARI) is(n)=n%(2^hammingweight(n)-1)==0 \\ Charles R Greathouse IV, Aug 04 2016

CROSSREFS

Cf. A038573, A292777.

Sequence in context: A023759 A004742 A277817 * A140181 A038032 A010408

Adjacent sequences:  A100287 A100288 A100289 * A100291 A100292 A100293

KEYWORD

base,easy,nonn

AUTHOR

Marc LeBrun, Nov 11 2004

STATUS

approved

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Last modified June 25 10:10 EDT 2019. Contains 324351 sequences. (Running on oeis4.)