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.

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

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: A047170 A333218 A349051 * A262308 A355137 A352641

Adjacent sequences: A137251 A137252 A137253 * A137255 A137256 A137257

Keyword

easy,nonn,base

Author

Ctibor O. Zizka, Mar 11 2008

Status

approved