

A173931


Primitive numbers k such that m/k is in the Cantor set for some m.


4



4, 10, 13, 28, 40, 82, 91, 121, 146, 182, 205, 244, 328, 364, 386, 656, 671, 730, 757, 820, 949, 1036, 1093, 1342, 1640, 2044, 2188, 2362, 2555, 2644, 2684, 2812, 2920, 3280, 3640, 3796, 3851, 4088, 4561, 4745, 5110, 6176, 6562, 6643, 7381, 7592, 7913
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OFFSET

1,1


COMMENTS

Primitive means no k is a multiple of 3. This is sequence A054591 without the multiples of 3. Sequence A173793 is a subsequence. Sequence A173932 gives the least m such for each k. Sequence A173933 gives the number of m < k/2 such that m/k is in the Cantor set. Irregular triangle A173934 gives a row of m values for each k.
The remaining terms <10000 are 9139, 9490, 9841.
It is assumed that gcd(m,k) = 1.


LINKS

T. D. Noe, Table of n, a(n) for n=1..185


MATHEMATICA

InCantorQ[m_, n_] := !MemberQ[Union[Flatten[RealDigits[m/n, 3][[1]]]], 1]; cantor=Reap[Do[If[Mod[n, 3] > 0, s=Select[Range[Ceiling[n/2]], GCD[n, # ]==1 && InCantorQ[ #, n] &]; If[s != {}, Sow[{n, s}]]], {n, 10000}]][[2, 1]]; First[Transpose[cantor]]


CROSSREFS

Sequence in context: A139121 A079932 A191107 * A173793 A076270 A032821
Adjacent sequences: A173928 A173929 A173930 * A173932 A173933 A173934


KEYWORD

nonn


AUTHOR

T. D. Noe, Mar 03 2010


STATUS

approved



