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A071594 Number of 1's in binary representation of n equals omega(n), the number of distinct primes in n factorization. 5
2, 4, 6, 8, 10, 12, 16, 18, 20, 24, 32, 33, 34, 36, 40, 42, 48, 64, 65, 68, 70, 72, 80, 84, 96, 128, 129, 136, 138, 140, 144, 160, 168, 192, 210, 256, 266, 272, 273, 276, 280, 288, 290, 320, 322, 330, 336, 384, 385, 390, 420, 512, 513, 514, 518, 522, 530, 532 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Ivan Neretin, Table of n, a(n) for n = 1..2000

EXAMPLE

129=10000001 in base 2 and 129=3*43 hence 129 is in the sequence.

MATHEMATICA

Select[Range[2, 1000], Length[FactorInteger[#]] == DigitCount[#, 2, 1] &] (* Ivan Neretin, May 30 2015 *)

PROG

(PARI) for(n=1, 1000, if(sum(i=1, length(binary(n)), component(binary(n), i))==omega(n), print1(n, ", ")))

(PARI) select(n->hammingweight(n)==omega(n), vector(1000, n, n)) \\ Michel Marcus, May 30 2015

CROSSREFS

Cf. A071595, A071596, A071814.

Sequence in context: A151999 A267817 A177917 * A306263 A071596 A090778

Adjacent sequences:  A071591 A071592 A071593 * A071595 A071596 A071597

KEYWORD

base,easy,nonn

AUTHOR

Benoit Cloitre, Jun 01 2002

STATUS

approved

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Last modified November 14 20:11 EST 2019. Contains 329129 sequences. (Running on oeis4.)