Dropping times in the 3x+1 (Collatz) iteration of 2^n-1.
2, 4, 7, 7, 56, 54, 15, 13, 18, 18, 58, 51, 43, 43, 51, 48, 100, 89, 56, 54, 64, 54, 137, 113, 146, 143, 73, 73, 121, 121, 115, 110, 123, 123, 138, 138, 130, 129, 123, 119, 119, 119, 203, 203, 203, 165, 143, 143, 143, 143, 138, 138, 211, 211, 135, 132, 207
1
It is curious that the plot consists of short lines.
T. D. Noe, Plot of 1000 terms
T. D. Noe, Table of 1000 terms
(Mma) Collatz[n_] := Most[NestWhileList[If[EvenQ[#], #/2, (3 # + 1)/2] &, n, # >= n &]]; Join[{2}, Table[Length[Collatz[2^n - 1]], {n, 2, 100}]]
Cf. S000258 (Collatz iteration on odd numbers), S000262.
nonn
T. D. Noe, Sep 19 2014