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 A119827 Number of ternary words with exactly one 000. 2

%I

%S 0,0,0,1,4,16,60,212,728,2444,8064,26256,84576,270048,855936,2696080,

%T 8446912,26341696,81812544,253181888,781005440,2402311616,7370247168,

%U 22558917120,68901651456,210037106688,639127277568,1941624275200

%N Number of ternary words with exactly one 000.

%C Except for the initial three zeros, convolution of A077835 with itself. Column 1 of A119825.

%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (4,0,-4,-12,-8,-4).

%F G.f.=z^3/(1-2z-2z^2-2z^3)^2.

%e a(4)=4 because we have 0001, 0002, 1000 and 2000.

%p h:=z^3/(1-2*z-2*z^2-2*z^3)^2: hser:=series(h,z=0,33): seq(coeff(hser,z,n), n=0..30);

%Y Cf. A077835, A119825, A119826.

%K nonn,easy

%O 0,5

%A _Emeric Deutsch_, May 26 2006

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Last modified September 20 21:19 EDT 2019. Contains 327247 sequences. (Running on oeis4.)