OFFSET
1,2
LINKS
T. D. Noe, Table of n, a(n) for n = 1..1000
EXAMPLE
6 is in the list because Collatz trajectory of 6 is {6, 3, 10, 5, 16, 8, 4, 2, 1} and number of steps to reach largest = number of steps to reach 1 from largest = 4.
MATHEMATICA
Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3*# + 1] &, n, # > 1 &]; Select[Range[50000], Position[Collatz[#], Max[Collatz[#]]] == {{(Length[Collatz[#]] + 1)/2}} &]
CROSSREFS
KEYWORD
nonn
AUTHOR
Jayanta Basu, Apr 03 2013
STATUS
approved