A185455 Trajectory of 7 under repeated application of the map in A185452.

7, 18, 9, 23, 58, 29, 73, 183, 458, 229, 573, 1433, 3583, 8958, 4479, 11198, 5599, 13998, 6999, 17498, 8749, 21873, 54683, 136708, 68354, 34177, 85443, 213608, 106804, 53402, 26701, 66753, 166883, 417208, 208604, 104302, 52151, 130378, 65189, 162973, 407433, 1018583, 2546458, 1273229, 3183073, 7957683, 19894208, 9947104

Offset

1,1

Comments

It is conjectured that this trajectory is unbounded, but this is an open problem.

References

J. C. Lagarias, ed., The Ultimate Challenge: The 3x+1 Problem, Amer. Math. Soc., 2010; see page 89.

Links

Rémy Sigrist, Table of n, a(n) for n = 1..10000

Index entries for sequences related to 3x+1 (or Collatz) problem

Maple

f:=n->if n mod 2 = 0 then n/2 else (5*n+1)/2; fi;
T:=proc(n, M) global f; local t1, i; t1:=[n];
for i from 1 to M-1 do t1:=[op(t1), f(t1[nops(t1)])]; od: t1; end;
T(7, 120);

Crossrefs

Cf. A185452, A185453, A185454.

Sequence in context: A113613 A070415 A034083 * A103570 A223247 A091832

Adjacent sequences: A185452 A185453 A185454 * A185456 A185457 A185458

Keyword

nonn

Author

N. J. A. Sloane, Feb 04 2011

Status

approved