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A024836
a(n) = least m such that if r and s in {1/1, 1/4, 1/7, ..., 1/(3n-2)} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.
4
3, 13, 29, 51, 92, 131, 193, 248, 331, 401, 505, 590, 715, 852, 963, 1121, 1291, 1427, 1618, 1821, 1981, 2205, 2441, 2625, 2882, 3151, 3361, 3651, 3953, 4267, 4511, 4846, 5193, 5552, 5829, 6209, 6601, 7005, 7315, 7740, 8177, 8626, 9087, 9441, 9923, 10417, 10923, 11441
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/(3*Range[50]-2), #] &, Range[5]];
t[[2]] (* A024836 *)
(* Peter J. C. Moses, Aug 06 2012 *)
CROSSREFS
KEYWORD
nonn
STATUS
approved