Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #10 May 19 2024 20:39:26
%S 6,30,120,600,2520,12600,57960,280560,1330560,6394680,30548760,
%T 146516040,701454000,3361690080,16104243120
%N Number of length-n 0..5 arrays connected end-around, with no sequence of L<n elements immediately followed by itself (periodic "squarefree").
%C Column 5 of A215228.
%e Some solutions for n=8:
%e ..3....0....1....3....0....0....3....3....0....3....3....3....0....0....4....0
%e ..2....2....5....4....1....4....4....2....4....1....2....4....3....2....0....2
%e ..1....1....4....2....0....5....0....0....0....4....5....1....1....3....4....5
%e ..2....0....3....1....3....1....3....5....1....0....4....5....0....2....3....2
%e ..0....3....5....5....4....3....1....2....5....3....0....0....4....4....5....0
%e ..5....4....0....3....0....4....5....4....4....1....3....1....5....3....0....5
%e ..2....2....3....1....4....5....2....2....1....2....1....0....0....2....2....1
%e ..5....4....4....0....3....1....1....0....5....5....5....5....4....5....1....5
%Y Cf. A215228.
%K nonn,more
%O 1,1
%A _R. H. Hardin_, Aug 06 2012