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A045110 Numbers whose base-4 representation contains no 1's and exactly one 3. 1
3, 11, 12, 14, 35, 43, 44, 46, 48, 50, 56, 58, 131, 139, 140, 142, 163, 171, 172, 174, 176, 178, 184, 186, 192, 194, 200, 202, 224, 226, 232, 234, 515, 523, 524, 526, 547, 555, 556, 558, 560, 562, 568, 570, 643, 651, 652, 654, 675 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
From Robert Israel, Apr 10 2018: (Start)
If k is in the sequence, then so are 4*k and 4*k+2.
All even terms of the sequence are obtained in this way.
The odd terms of the sequence are 4*k+3 for k in A062880. (End)
LINKS
MAPLE
f:= proc(i, x, d) local j, X, nX;
X:= convert(x, base, 2); nX:= nops(X);
3*4^i+add(X[j]*2*4^`if`(j<=i, j-1, j), j=1..nX)
end proc:
sort([seq(seq(seq(f(i, x, d), x=`if`(i=d-1, 0, 2^(d-2))..2^(d-1)-1), i=0..d-1), d=0..6)]); # Robert Israel, Apr 10 2018
MATHEMATICA
Select[Range[700], DigitCount[#, 4, 1]==0&&DigitCount[#, 4, 3]==1&] (* Harvey P. Dale, Jul 23 2018 *)
CROSSREFS
Sequence in context: A043051 A024545 A101134 * A055046 A141386 A254220
KEYWORD
nonn,base
AUTHOR
STATUS
approved

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Last modified April 19 16:52 EDT 2024. Contains 371794 sequences. (Running on oeis4.)