Dropping times of numbers 3+4*n in the 3x+1 problem (or the Collatz problem).

4, 7, 5, 7, 4, 5, 59, 56, 4, 8, 5, 54, 4, 5, 7, 54, 4, 51, 5, 8, 4, 5, 45, 8, 4, 42, 5, 31, 4, 5, 8, 15, 4, 7, 5, 7, 4, 5, 40, 21, 4, 29, 5, 8, 4, 5, 7, 13, 4, 8, 5, 13, 4, 5, 8, 31, 4, 12, 5, 20, 4, 5, 27, 13, 4, 7, 5, 7, 4, 5, 24, 10, 4, 8, 5, 13, 4, 5, 7, 21

1

This is similar to A126241, but without the terms starting with 2*n and 4*n+1. See S000258 for a less restrictive version.

T. D. Noe, Plot of 10000 terms

T. D. Noe, Table of 10000 terms

(Mma) Table[cnt = 1; m = n; While[If[EvenQ[m], m = m/2, m = (3*m + 1)/2]; m > n, cnt++]; cnt, {n, 3, 399, 4}]

Cf. A126241.

nonn

T. D. Noe, Sep 17 2014