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A305694 Number of length-n binary words containing no instance of the pattern x y y x^R where x and y are nonempty. 0

%I

%S 1,2,4,8,12,18,22,28,38,50,56,68,84,102,118,142,172,204,228,264,308,

%T 358,412,478,558,654,764,892,1048,1234,1404,1618,1870,2152,2458,2826,

%U 3256,3750,4292,4940,5688,6548,7518,8672,10004,11520,13184,15130,17364,19904

%N Number of length-n binary words containing no instance of the pattern x y y x^R where x and y are nonempty.

%C By an "instance of the pattern x y y x^R" we mean a nonempty block, followed by a second nonempty block (of a possibly different length), followed by the second block again, and ending with the first block reversed. An example in English is the word "redder": (re)(d)(d)(er).

%K nonn

%O 0,2

%A _Jeffrey Shallit_, Jun 08 2018

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Last modified September 15 08:37 EDT 2019. Contains 327062 sequences. (Running on oeis4.)