OFFSET
1,2
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Collatz Problem
Wikipedia, Collatz conjecture
MATHEMATICA
coll[n_]:=NestWhileList[If[EvenQ[#], #/2, 3#+1]&, n, #>1&]; Select[Range[101], Complement[Divisors[#], coll[#]]=={}&] (* Jayanta Basu, May 27 2013 *)
PROG
(Haskell)
import Data.List (intersect)
a207674 n = a207674_list !! (n-1)
a207674_list = filter
(\x -> a027750_row x `intersect` a070165_row x == a027750_row x) [1..]
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Feb 20 2012
STATUS
approved