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%I #13 Oct 15 2018 18:57:45
%S 2,3,6,3,3,7,3,3,3,3,3,7,3,3,3,3,3,3,3,3,3,3,3,7,3,3,3,3,3,3,3,3,3,3,
%T 3,3,3,3,3,3,3,3,3,3,3,3,3,7,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
%U 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3
%N Smallest number not in Collatz trajectory starting at n.
%C a(n) <= 7; a(A007283(n)) = 7;
%C a(n) <> 4; a(n) <> 4; a(n) <> 6 for n > 3;
%C a(n) = A216022(n) + 1.
%H Reinhard Zumkeller, <a href="/A216059/b216059.txt">Table of n, a(n) for n = 1..1000</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/CollatzProblem.html">Collatz Problem</a>
%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Collatz_conjecture">Collatz conjecture</a>
%H <a href="/index/3#3x1">Index entries for sequences related to 3x+1 (or Collatz) problem</a>
%t scoll[n_]:=Sort[NestWhileList[If[EvenQ[#],#/2,3#+1] &,n,#>1 &]]; Join[{2,3},Table[i=1; While[scoll[n][[i]]==i,i++]; i,{n,3,86}]] (* _Jayanta Basu_, May 27 2013 *)
%o (Haskell)
%o import Data.List ((\\))
%o a216059 n = head $ enumFromTo 1 (maximum ts + 1) \\ ts
%o where ts = a070165_row n
%Y Cf. A006370, A070165.
%K nonn
%O 1,1
%A _Reinhard Zumkeller_, Sep 01 2012
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