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A084561 Numbers with a square number of 1's in their binary expansion. 2
0, 1, 2, 4, 8, 15, 16, 23, 27, 29, 30, 32, 39, 43, 45, 46, 51, 53, 54, 57, 58, 60, 64, 71, 75, 77, 78, 83, 85, 86, 89, 90, 92, 99, 101, 102, 105, 106, 108, 113, 114, 116, 120, 128, 135, 139, 141, 142, 147, 149, 150, 153, 154, 156, 163, 165, 166, 169, 170, 172, 177, 178 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Begins to differ from A084345 at the 22nd term.

There are A003099(n) terms with at most n bits, so a(n) is n sqrt log n times a bounded function of n (which does not tend toward a limit). - Charles R Greathouse IV, Mar 26 2013

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

MATHEMATICA

Select[Range[0, 178], IntegerQ[Sqrt[Count[IntegerDigits[#, 2], 1]]]&] (* Jayanta Basu, May 24 2013 *)

PROG

(PARI) is(n)=issquare(hammingweight(n)) \\ Charles R Greathouse IV, Mar 26 2013

CROSSREFS

Cf. A001969, A000069, A052294, A084345.

Sequence in context: A019278 A267894 A084345 * A277166 A078613 A072202

Adjacent sequences:  A084558 A084559 A084560 * A084562 A084563 A084564

KEYWORD

easy,nonn,base

AUTHOR

Jason Earls, Jun 27 2003

STATUS

approved

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Last modified August 12 23:19 EDT 2020. Contains 336440 sequences. (Running on oeis4.)