S000274


Records in the lengths of the Collatz (3x+1) iteration.

0, 1, 5, 6, 11, 13, 14, 16, 70, 71, 73, 75, 77, 79, 81, 83, 91, 92, 108, 113, 115, 116, 132, 137, 150, 165, 169, 174, 176, 178, 194, 196, 204, 214, 221, 223, 236, 241, 243, 278, 282, 295, 319, 329, 331, 333, 349, 351, 353, 366, 374, 384, 416, 429, 431, 433

1

S000274

Here we use the (3x+1)/2 step instead of 3x+1 that A006878 uses.

T. D. Noe, Plot of 130 terms

T. D. Noe, Table of 130 terms

Eric W. Weisstein, Collatz Problem

(Mma) Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, (3*# + 1)/2] &, n, # > 1 &]; (* this function is applied to the numbers in A006877 *)

Cf. A006877 (numbers that produce the lengths here).

nonn

T. D. Noe, Oct 03 2014

© Tony D Noe 2014-2015