

A026138


Numbers k such that s(j) < s(k) for all j < k, where s = A026136.


7



1, 2, 4, 5, 8, 10, 11, 13, 14, 17, 20, 22, 23, 26, 28, 29, 31, 32, 35, 37, 38, 40, 41, 44, 47, 49, 50, 53, 56, 58, 59, 62, 64, 65, 67, 68, 71, 74, 76, 77, 80, 82, 83, 85, 86, 89, 91, 92, 94, 95, 98, 101, 103, 104, 107, 109, 110, 112, 113
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OFFSET

1,2


COMMENTS

Also a(n) = (1/2)*s(n+1), where s = A026169.
That these definitions produce the same sequence can be established using the methods in the Dekking paper.
Indices of records in A026136.  Michael De Vlieger, Aug 27 2021


LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..10000
F. M. Dekking, Permutations of N generated by leftright filling algorithms, arXiv:2001.08915 [math.CO], 2020.


MATHEMATICA

Block[{a, r, s, nn = 113}, a[1] = 1; Do[If[! IntegerQ[a[#1]], Set[a[#1], i], Set[a[#2], i]] & @@ {i  #, i + #} &@ Floor[i/2], {i, 2 nn}]; s = TakeWhile[Array[a[#] &, nn], IntegerQ]; Map[FirstPosition[s, #][[1]] &, Union@ FoldList[Max, s]]] (* Michael De Vlieger, Aug 27 2021 *)


CROSSREFS

Cf. A026136, A026139 (records in A026136), A026169.
Sequence in context: A325442 A134191 A286803 * A026170 A026174 A120685
Adjacent sequences: A026135 A026136 A026137 * A026139 A026140 A026141


KEYWORD

nonn


AUTHOR

Clark Kimberling


EXTENSIONS

Edited by N. J. A. Sloane, Jan 31 2020


STATUS

approved



