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 A064664 Regard A064413 as giving a permutation of the positive integers; sequence gives inverse permutation. 21
 1, 2, 5, 3, 10, 4, 14, 8, 6, 9, 20, 7, 28, 13, 11, 17, 33, 12, 37, 18, 15, 19, 43, 16, 24, 27, 22, 26, 57, 23, 61, 31, 21, 32, 25, 30, 67, 36, 29, 40, 74, 35, 81, 41, 39, 42, 89, 45, 50, 46, 34, 47, 100, 48, 53, 49, 38, 56, 107, 52, 115, 60, 51, 64, 54, 59, 128, 65, 44, 55 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The Mathematica program computes the EKG sequence A064413 and then determines the inverse permutation. - T. D. Noe, Nov 13 2002 LINKS T. D. Noe and Ray Chandler, Table of n, a(n) for n = 1..10000 (first 1000 terms from T. D. Noe) J. C. Lagarias, E. M. Rains and N. J. A. Sloane, The EKG sequence, Exper. Math. 11 (2002), 437-446. Eric Weisstein's World of Mathematics, EKG Sequence EXAMPLE Original permutation has cycles (1) (2) (3, 4, 6, 9, 10, 5) ( ..., 20, 18, 12, 7, 14, 13, 28, 26, ...) (8) ... MATHEMATICA maxN=200; lst={1, 2}; unused=Range[3, maxN]; found=True; While[found, found=False; i=0; While[ !found&&i1, found=True; AppendTo[lst, unused[[i]]]; unused=Delete[unused, i]]]]; Take[Ordering[lst], unused[[1]]-1] PROG (Haskell) import Data.List (elemIndex); import Data.Maybe (fromJust) a064664 = (+ 1) . fromJust . (`elemIndex` a064413_list) -- Reinhard Zumkeller, May 01 2014, Sep 17 2011 CROSSREFS Cf. A064413, A064665-A064669. Equals A064421 + 1. Sequence in context: A163233 A096666 A191855 * A078386 A163254 A277696 Adjacent sequences:  A064661 A064662 A064663 * A064665 A064666 A064667 KEYWORD nonn AUTHOR N. J. A. Sloane, Oct 11 2001 STATUS approved

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Last modified January 18 05:30 EST 2019. Contains 319269 sequences. (Running on oeis4.)