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 A098551 Inverse of A098550. 12
 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 (list; graph; refs; listen; history; text; internal format)
 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. 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

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Last modified July 30 02:04 EDT 2021. Contains 346346 sequences. (Running on oeis4.)