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A098003
Start with positive integers. On the m-th step, shift terms a(m+1) to a(2m-1) one position to the left, then move a(m) to position (2m-1). Sequence is limit of reordering.
4
1, 3, 4, 2, 7, 8, 6, 11, 12, 9, 15, 16, 5, 19, 20, 14, 23, 24, 17, 27, 28, 13, 31, 32, 22, 35, 36, 25, 39, 40, 18, 43, 44, 30, 47, 48, 33, 51, 52, 10, 55, 56, 38, 59, 60, 41, 63, 64, 29, 67, 68, 46, 71, 72, 49, 75, 76, 34, 79, 80, 54, 83, 84, 57, 87, 88, 26, 91, 92
OFFSET
1,2
COMMENTS
An analysis of this sequence was provided by Keith Ramsay - see link.
EXAMPLE
[1,2,3,4,5,6,...] -> [1,3,2,4,5,6,...] -> [1,3,4,5,2,6,...] -> [1,3,4,2,6,7,...] -> [1,3,4,2,7,5,...] -> [1,3,4,2,7,8,...] -> ...
MATHEMATICA
mx = 69; Take[Fold[Insert[Delete[#1, #2], #1[[#2]], 2 #2 - 1] &, Range[2 mx], Range[mx]], mx] (* Ivan Neretin, Mar 05 2016 *)
CROSSREFS
Cf. A098046 for inverse permutation, A098486 auxiliary sequence explaning the behavior of column 1, if the sequence is written in a 3-entries-per-line table.
Sequence in context: A216221 A296431 A045901 * A026245 A266693 A026178
KEYWORD
nonn
AUTHOR
Leroy Quet, Sep 08 2004
EXTENSIONS
More terms from Hugo Pfoertner, Sep 08 2004
STATUS
approved