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A024842
a(n) = least m such that if r and s in {1/2, 1/4, 1/6, ..., 1/2n} satisfy r < s, then r < k/m < (k+2)/m < s for some integer k.
3
11, 29, 55, 89, 131, 181, 253, 323, 417, 505, 621, 727, 865, 989, 1149, 1291, 1473, 1633, 1837, 2053, 2243, 2481, 2731, 2949, 3221, 3505, 3751, 4057, 4375, 4649, 4989, 5341, 5643, 6017, 6403, 6733, 7141, 7561, 7993, 8363, 8817, 9283, 9761, 10169, 10669, 11181, 11705
OFFSET
2,1
COMMENTS
For a guide to related sequences, see A001000. - Clark Kimberling, Aug 12 2012
LINKS
MATHEMATICA
leastSeparatorS[seq_, s_] := Module[{n = 1},
Table[While[Or @@ (Ceiling[n #1[[1]]] <
s + 1 + Floor[n #1[[2]]] &) /@ (Sort[#1, Greater] &) /@
Partition[Take[seq, k], 2, 1], n++]; n, {k, 2, Length[seq]}]];
t = Map[leastSeparatorS[1/(2*Range[50]), #] &, Range[5]];
t[[3]] (* A024842 *)
(* Peter J. C. Moses, Aug 06 2012 *)
CROSSREFS
Sequence in context: A364894 A082108 A024846 * A304275 A031072 A193880
KEYWORD
nonn
STATUS
approved