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%I #21 Mar 08 2016 18:26:48
%S 1,5,20,71,237,761,2377,7278,21945,65375,192861,564387,1640496,
%T 4741103,13634501,39042437,111379025,316687006,897796581,2538530615,
%U 7160768785,20156241155,56626360256,158804376883,444638710925,1243115597929,3470779612521,9678320566654
%N Number of ternary strings of length n with maximal run length two containing 112.
%H Math StackExchange, <a href="http://math.stackexchange.com/questions/1685843">Words built with 0,1,2</a>
%H Marko Riedel, <a href="/A269914/a269914.maple.txt">Maple code by total enumeration and by generating function.</a>
%F G.f.: x^3*(x+1)*(x^2+x+1)/((2*x^2+2*x-1)*(x^4+3*x^3+3*x^2+x-1)).
%t Drop[CoefficientList[Series[x^3 (x + 1) (x^2 + x + 1)/((2 x^2 + 2 x - 1) (x^4 + 3 x^3 + 3 x^2 + x - 1)), {x, 0, 30}], x], 3] (* _Michael De Vlieger_, Mar 08 2016 *)
%Y Cf. A081038, A269915, A269916, A269917.
%K nonn
%O 3,2
%A _Marko Riedel_, Mar 07 2016
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