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.

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

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]-2), #] &, Range[5]];
t[[2]] (* A024836 *)
(* Peter J. C. Moses, Aug 06 2012 *)

Crossrefs

Cf. A001000, A024837, A024838.

Sequence in context: A049043 A031378 A144391 * A227541 A023553 A268184

Adjacent sequences: A024833 A024834 A024835 * A024837 A024838 A024839

Keyword

nonn

Author

Clark Kimberling

Status

approved