

A228014


Numbers k whose Collatz sequence length is greater than k+1 (counting both the x/2 and the 3x+1 steps).


2



3, 6, 7, 9, 11, 14, 15, 18, 19, 27, 31, 41, 47, 54, 55, 62, 63, 71, 73, 82, 83, 91, 94, 95, 97, 108, 109, 110
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OFFSET

1,1


LINKS

Table of n, a(n) for n=1..28.
Index entries for sequences related to 3x+1 (or Collatz) problem


EXAMPLE

a(1) is 3 because its Collatz sequence has eight steps: 3, 10, 5, 16, 8, 4, 2, 1.


MATHEMATICA

Select[Range[1000], Length[Collatz[#]] > #+1 &] (* T. D. Noe, Aug 20 2013 *)


CROSSREFS

Cf. A082984 (allows number of steps equal to n).
Sequence in context: A188974 A047558 A160217 * A188971 A176065 A333552
Adjacent sequences: A228011 A228012 A228013 * A228015 A228016 A228017


KEYWORD

nonn,more


AUTHOR

Gonzalo Ciruelos, Aug 02 2013


STATUS

approved



