S001020


For even n, the number of Collatz (3x+1) iteration terms greater than n.

0, 0, 3, 0, 1, 1, 8, 0, 7, 0, 4, 0, 1, 3, 8, 0, 2, 2, 5, 0, 1, 1, 5, 0, 4, 0, 95, 0, 1, 4, 91, 0, 3, 0, 3, 0, 1, 1, 10, 0, 89, 0, 5, 0, 1, 2, 85, 0, 2, 0, 3, 0, 1, 83, 87, 0, 4, 0, 6, 1, 2, 80, 85, 0, 2, 0, 3, 0, 1, 1, 78, 0, 83, 0, 4, 0, 1, 4, 9, 0, 2, 75, 78

1

S001020

This is similar to the odd case in S001019.

T. D. Noe, Plot of 5000 terms

T. D. Noe, Table of 5000 terms

Wikipedia, Collatz conjecture

(Mma) Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; Table[Length[Select[Collatz[n], # > n &]], {n, 2, 200, 2}]

Cf. A222597S001016, S001019.

nonn

T. D. Noe, May 09 2017

© Tony D Noe 2014-2017