OFFSET
1,3
LINKS
T. D. Noe, Table of n, a(n) for n = 1..10000
MATHEMATICA
Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; Table[Length[Select[Collatz[n], # > n &]], {n, 100}]
PROG
(PARI) a(n)=my(k=n, s); while(k>1, k=if(k%2, 3*k+1, k/2); if(k>n, s++)); s \\ Charles R Greathouse IV, Aug 26 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe, Mar 01 2013
STATUS
approved