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 A133420 Number of steps to reach 1 under repeated applications of the "5x+1" map of A133419, or -1 if 1 is never reached. 4
 0, 1, 1, 2, 14, 2, 5, 3, 2, 15, 9, 3, 12, 6, 15, 4, 9, 3, 7, 16, 6, 10, 21, 4, 9, 13, 3, 7, 18, 16, 16, 5, 10, 10, 14, 4, 19, 8, 13, 17, 13, 7, 7, 11, 16, 22, 26, 5, 16, 10, 10, 14, 25, 4, 25, 8, 8, 19, 23, 17, 13, 17, 7, 6, 17, 11, 11, 11, 22, 15, 26, 5, 16, 20, 10, 9, 20, 14, 14, 18, 4, 14 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS The 5x+1 map sends x to x/2 if x is even, x/3 if x is divisible by 3, otherwise 5x+1. LINKS R. J. Mathar, Table of n, a(n) for n = 1..20000 R. J. Mathar, Maple program to make b-file Tomás Oliveira e Silva, The px+1 problem Index entries for sequences related to 3x+1 (or Collatz) problem CROSSREFS Cf. A133419. Sequence in context: A196815 A260120 A221234 * A227628 A298800 A138907 Adjacent sequences: A133417 A133418 A133419 * A133421 A133422 A133423 KEYWORD nonn,easy AUTHOR N. J. A. Sloane, Nov 27 2007 STATUS approved

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Last modified December 4 18:39 EST 2023. Contains 367563 sequences. (Running on oeis4.)