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Number of length n 0..4 arrays connected end-around, with no sequence of L<n elements immediately followed by itself ("periodic squarefree"), and new values introduced in order 0..4.
0

%I #6 Jun 26 2017 23:08:02

%S 1,1,1,3,6,26,84,324,1170,4412,16313,61138,227383,849667,3168419,

%T 11831104,44144206,164792736,615027929,2295714687

%N Number of length n 0..4 arrays connected end-around, with no sequence of L<n elements immediately followed by itself ("periodic squarefree"), and new values introduced in order 0..4.

%C Column 4 of A215401.

%e Some solutions for n=6:

%e ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0

%e ..1....1....1....1....1....1....1....1....1....1....1....1....1....1....1....1

%e ..2....0....2....2....2....2....2....2....2....2....2....2....0....0....2....2

%e ..3....2....3....1....0....3....3....1....3....1....1....3....2....2....0....3

%e ..2....1....1....0....3....1....4....3....4....0....3....0....3....3....1....2

%e ..4....2....3....2....1....2....2....2....3....3....1....4....4....2....3....1

%K nonn

%O 1,4

%A _R. H. Hardin_, Aug 09 2012