A026140 - OEIS

A026140

a(n) = (1/2)*(s(n) - 1), where s = A026139.

0, 1, 3, 4, 7, 9, 10, 12, 13, 16, 19, 21, 22, 25, 27, 28, 30, 31, 34, 36, 37, 39, 40, 43, 46, 48, 49, 52, 55, 57, 58, 61, 63, 64, 66, 67, 70, 73, 75, 76, 79, 81, 82, 84, 85, 88, 90, 91, 93, 94, 97, 100, 102, 103, 106, 108, 109, 111, 112, 115, 117, 118

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OFFSET

1,3

LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..5004

MATHEMATICA

Block[{a, r, s, nn = 119}, 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[#] &, 2 nn], IntegerQ]; Map[(1/2) (# - 1) &, Union@ FoldList[Max, s]]] (* Michael De Vlieger, Aug 27 2021 *)

CROSSREFS

Cf. A026136, A026139.

Sequence in context: A300061 A300789 A026225 * A233010 A263488 A344416

Adjacent sequences: A026137 A026138 A026139 * A026141 A026142 A026143

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved