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A169837 EKG sequence started at 3 instead of 2.

%I A169837 #8 May 16 2019 01:32:32
%S A169837 3,6,2,4,8,10,5,15,9,12,14,7,21,18,16,20,22,11,33,24,26,13,39,27,30,
%T A169837 25,35,28,32,34,17,51,36,38,19,57,42,40,44,46,23,69,45,48,50,52,54,56,
%U A169837 49,63,60,55,65,70,58,29,87,66,62,31,93,72,64,68,74,37,111,75,78,76,80,82,41
%N A169837 EKG sequence started at 3 instead of 2.
%C A169837 A generalization of A064413.
%C A169837 a(n) = A064413(n+1) for n > 43; a(n) = A169849(n) for n > 9. - _Reinhard Zumkeller_, Jul 04 2014
%H A169837 Reinhard Zumkeller, <a href="/A169837/b169837.txt">Table of n, a(n) for n = 1..10000</a>
%H A169837 Gordon Hamilton, <a href="http://www.youtube.com/watch?v=yd2jr30K2R4">The EKG Sequence and the Tree of Numbers</a>
%H A169837 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.Com/EKGSequence.html">EKG Sequence</a>
%H A169837 <a href="/index/Ed#EKG">Index entries for sequences related to EKG sequence</a>
%o A169837 (Haskell)
%o A169837 import Data.List (delete)
%o A169837 a169837 n = a169837_list !! (n-1)
%o A169837 a169837_list = 3 : ekg 3 (2 : [4..]) where
%o A169837    ekg x zs = f zs where
%o A169837        f (y:ys) = if gcd x y > 1 then y : ekg y (delete y zs) else f ys
%o A169837 -- _Reinhard Zumkeller_, Jul 04 2014
%Y A169837 Cf. A064413, A064417, A169849.
%K A169837 nonn
%O A169837 1,1
%A A169837 _T. D. Noe_ and _N. J. A. Sloane_, Jun 02 2010