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A137254 Numbers n for which r(n) = 3 * S(n)/2, where r(n) = number of digits of n and S(n) = sum of digits of n; n in binary notation. 2
5, 6, 39, 43, 45, 46, 51, 53, 54, 57, 58, 60, 287, 303, 311, 315, 317, 318, 335, 343, 347, 349, 350, 359, 363, 365, 366, 371, 373, 374, 377, 378, 380, 399, 407, 411, 413, 414, 423, 427, 429, 430, 435, 437, 438, 441, 442, 444, 455, 459, 461, 462, 467, 469, 470 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Integers n such that in Base 2, number of `1`'s = twice number of `0`'s. IntegerDigits[43,2]={1,0,1,0,1,1},IntegerDigits[60,2]={1,1,1,1,0,0},... - Vladimir Joseph Stephan Orlovsky, Jul 21 2009

LINKS

Table of n, a(n) for n=1..55.

MATHEMATICA

f0[n_]:=DigitCount[n, 2, 0]; f1[n_]:=DigitCount[n, 2, 1]; f[n_]:=f1[n]/f0[n]; lst={}; Do[If[f[n]==2, AppendTo[lst, n]], {n, 6!}]; lst (* Vladimir Joseph Stephan Orlovsky, Jul 21 2009 *)

Select[Range[500], DigitCount[#, 2, 1]==2*DigitCount[#, 2, 0]&] (* Harvey P. Dale, May 22 2013 *)

PROG

(PARI) is(n)=hammingweight(n)==2/3*#binary(n) \\ Charles R Greathouse IV, May 28 2013

CROSSREFS

Cf. A000120, A070939, A225222.

Sequence in context: A253192 A036254 A047170 * A262308 A299168 A219516

Adjacent sequences:  A137251 A137252 A137253 * A137255 A137256 A137257

KEYWORD

easy,nonn,base

AUTHOR

Ctibor O. Zizka, Mar 11 2008

STATUS

approved

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Last modified October 17 18:58 EDT 2019. Contains 328127 sequences. (Running on oeis4.)