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 A198587 Odd numbers producing 4 odd numbers in the Collatz iteration. 3
 17, 35, 69, 75, 141, 151, 277, 301, 565, 605, 1109, 1137, 1205, 2261, 2275, 2417, 2421, 4437, 4549, 4821, 4835, 4849, 9045, 9101, 9669, 9685, 9699, 17749, 18197, 19285, 19341, 19397, 19417, 36181, 36405, 38677, 38741, 38797, 38833, 38835, 70997, 72789, 72817 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Vincenzo Librandi and T. D. Noe, Table of n, a(n) for n = 1..287 (first 134 terms from Vincenzo Librandi) MATHEMATICA Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; t = {}; Do[If[Length[Select[Collatz[n], OddQ]] == 4, AppendTo[t, n]], {n, 1, 100000, 2}]; t CROSSREFS Cf. A198584. Sequence in context: A239129 A212427 A195047 * A041570 A041572 A146729 Adjacent sequences:  A198584 A198585 A198586 * A198588 A198589 A198590 KEYWORD nonn AUTHOR T. D. Noe, Oct 31 2011 STATUS approved

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Last modified June 22 21:29 EDT 2021. Contains 345393 sequences. (Running on oeis4.)