A098551 Inverse of A098550.

1, 2, 3, 4, 9, 10, 15, 6, 5, 16, 22, 12, 23, 8, 7, 14, 30, 31, 43, 18, 17, 20, 51, 33, 11, 25, 19, 27, 61, 39, 62, 29, 24, 35, 13, 37, 79, 41, 21, 48, 87, 44, 88, 46, 26, 56, 101, 52, 40, 50, 28, 54, 114, 69, 34, 58, 47, 63, 127, 71, 132, 60, 42, 65, 36, 73, 142, 67, 49, 80, 153

Offset

1,2

Comments

Now known to be a permutation of the natural numbers: see the 2015 article by Applegate, Havermann, Selcoe, Shevelev, Sloane, and Zumkeller.

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

David L. Applegate, Hans Havermann, Bob Selcoe, Vladimir Shevelev, N. J. A. Sloane, and Reinhard Zumkeller, The Yellowstone Permutation, arXiv preprint arXiv:1501.01669 [math.NT], 2015.

Index entries for sequences that are permutations of the natural numbers

Formula

A098553(n) = a(a(n)).

Mathematica

f[lst_List] := Block[{k = 4}, While[ GCD[ lst[[-2]], k] == 1 || GCD[ lst[[-1]], k] > 1 || MemberQ[lst, k], k++]; Append[lst, k]]; Table[ Position[ Nest[ f, {1, 2, 3}, 120], n], {n, 71}] // Flatten (* Robert G. Wilson v, Nov 21 2014 *)

Prog

(Haskell)
import Data.List (elemIndex); import Data.Maybe (fromJust)
a098551 = (+ 1) . fromJust . (`elemIndex` a098550_list)
-- Reinhard Zumkeller, Nov 21 2014

Crossrefs

Cf. A098550, A098553.

Cf. A249943 (partial maxima).

Cf. A098479, A255940.

Sequence in context: A273907 A066105 A083180 * A249943 A251620 A128944

Adjacent sequences: A098548 A098549 A098550 * A098552 A098553 A098554

Keyword

nonn

Author

Reinhard Zumkeller, Sep 14 2004

Status

approved