A163140 Integers n such that in base 2, 3 `1`'s for each `0`.

11, 13, 14, 159, 175, 183, 187, 189, 190, 207, 215, 219, 221, 222, 231, 235, 237, 238, 243, 245, 246, 249, 250, 252, 2303, 2431, 2495, 2527, 2543, 2551, 2555, 2557, 2558, 2687, 2751, 2783, 2799, 2807, 2811, 2813, 2814, 2879, 2911, 2927, 2935, 2939, 2941

Offset

1,1

Comments

There are (4n-1 choose n) 4n-bit members of this sequence for each n=1,2,.... - Charles R Greathouse IV, Oct 12 2009

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

IntegerDigits[11,2]={1,0,1,1},..IntegerDigits[190,2]={1,0,1,1,1,1,1,0},..

Maple

sort([seq(op(map(proc(t) local j; 2^(4*n)-1-add(2^(j-1), j=t) end proc, combinat:-choose(4*n-1, n))), n=1..3)]);

Mathematica

f0[n_]:=DigitCount[n, 2, 0]; f1[n_]:=DigitCount[n, 2, 1]; f[n_]:=f1[n]/f0[n]; lst={}; Do[If[f[n]==3, AppendTo[lst, n]], {n, 7!}]; lst
Select[Range[3000], DigitCount[#, 2, 1]==3*DigitCount[#, 2, 0]&] (* Harvey P. Dale, May 31 2015 *)

Crossrefs

Cf. A031443, A137254, A000120

Sequence in context: A007934 A111347 A026818 * A048596 A228709 A358270

Adjacent sequences: A163137 A163138 A163139 * A163141 A163142 A163143

Keyword

nonn,base

Author

Vladimir Joseph Stephan Orlovsky, Jul 21 2009

Status

approved