A024837 a(n) = least m such that if r and s in {1/2, 1/5, 1/8, ..., 1/(3n-1)} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.

7, 21, 41, 67, 100, 155, 205, 281, 346, 443, 523, 641, 737, 876, 1027, 1149, 1321, 1505, 1651, 1856, 2073, 2243, 2481, 2731, 2993, 3197, 3480, 3775, 4082, 4321, 4649, 4989, 5341, 5613, 5986, 6371, 6768, 7073, 7491, 7921, 8363, 8702, 9165, 9640, 10127, 10626, 11009

Offset

2,1

Comments

For a guide to related sequences, see A001000. - Clark Kimberling, Aug 12 2012

Links

Clark Kimberling, Table of n, a(n) for n = 2..100

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]-1), #] &, Range[5]];
t[[2]] (* A024837 *)
(* Peter J. C. Moses, Aug 06 2012 *)

Crossrefs

Cf. A001000, A024836, A024838.

Sequence in context: A063292 A045524 A125228 * A205864 A162818 A024966

Adjacent sequences: A024834 A024835 A024836 * A024838 A024839 A024840

Keyword

nonn

Author

Clark Kimberling

Status

approved