A028395 Iterate the map in A006368 starting at 14.

14, 21, 16, 24, 36, 54, 81, 61, 46, 69, 52, 78, 117, 88, 132, 198, 297, 223, 167, 125, 94, 141, 106, 159, 119, 89, 67, 50, 75, 56, 84, 126, 189, 142, 213, 160, 240, 360, 540, 810, 1215, 911, 683, 512, 768, 1152, 1728, 2592, 3888, 5832, 8748, 13122, 19683

Offset: 0

Author

J. H. Conway

Keywords

• nonn

Links

• T. D. Noe, Table of n, a(n) for n = 0..1000
• J. H. Conway, On unsettleable arithmetical problems, Amer. Math. Monthly, 120 (2013), 192-198.
• D. Gale, Tracking the Automatic Ant And Other Mathematical Explorations, A Collection of Mathematical Entertainments Columns from The Mathematical Intelligencer, Springer, 1998; see p. 16.
• Index entries for sequences related to 3x+1 (or Collatz) problem

Crossrefs

Cf. A028393.

Cf. A180853, A180864, A182205; A028398(5) = 14.

Programs

Haskell

a028395 n = a028395_list !! n
a028395_list = iterate a006368 14  -- Reinhard Zumkeller, Apr 18 2012

Mathematica

SubstitutionSystem[{n_ :> If[EvenQ[n], 3n/2, Round[3n/4]]}, {14}, 60] // Flatten (* Jean-François Alcover, Mar 01 2019 *)

Formula

a(n+1) = A006368(a(n)).