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%I #18 Aug 15 2015 10:30:35
%S 1,4,37,4,89,89,1,89,37,1,4,89,1,89,16,16,89,37,1,20,89,89,1,20,89,16,
%T 89,1,89,37,1,1,37,89,89,89,37,58,37,16,89,42,89,1,89,89,37,89,1,89,
%U 16,89,89,89,89,37,37,58,37,89,37,16,89,89,37,89,89,1,16,1,89,89,58
%N Number in the 2-digitaddition sequence at which the eventually periodic part starts.
%C a(A007770(n)) = 1; a(A031177(n)) > 1. - _Reinhard Zumkeller_, Mar 16 2013
%H Reinhard Zumkeller, <a href="/A103369/b103369.txt">Table of n, a(n) for n = 1..10000</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Digitaddition.html">Digitaddition</a>
%e The 2-digitaddition sequence for n = 3 is {3, 9, 81, 65, 61, 37, 58, 89, 145, 42, 20, 4, 16, 37, ...}, so a(3) = 37.
%o (Haskell)
%o a103369 = until (`elem` a039943_list) a003132
%o a103369_list = map a103369 [1..]
%o -- _Reinhard Zumkeller_, Oct 17 2011, Aug 24 2011
%Y Cf. A007770, A031176, A003132, A039943.
%K nonn,base
%O 1,2
%A _Eric W. Weisstein_, Feb 02 2005