A225222 -id:A225222 - cp's OEIS frontend

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

Ctibor O. Zizka, Mar 11 2008

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

Cf. A000120, A070939, A225222.

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 *)

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

cp's OEIS Frontend

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.

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