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A268456 Number of length-n 0..7 arrays with no adjacent pair x,x+1 followed at any distance by x+1,x.

%I A268456 #4 Feb 04 2016 22:04:30
%S A268456 8,64,505,3977,31276,245626,1926444,15089356,118040270,922247248,
%T A268456 7196716310,56092274904,436681564144,3395712755366,26376195676360,
%U A268456 204653424502050,1586213921445534,12281469122143732,94993604706706795
%N A268456 Number of length-n 0..7 arrays with no adjacent pair x,x+1 followed at any distance by x+1,x.
%C A268456 Column 7 of A268457.
%H A268456 R. H. Hardin, <a href="/A268456/b268456.txt">Table of n, a(n) for n = 1..210</a>
%e A268456 Some solutions for n=5
%e A268456 ..7....2....3....3....6....4....5....4....1....0....6....7....6....4....2....4
%e A268456 ..6....5....2....6....5....4....1....1....6....2....1....4....5....1....4....1
%e A268456 ..4....4....1....4....0....5....3....0....4....4....7....5....0....3....7....7
%e A268456 ..5....4....1....5....1....0....4....7....3....2....2....3....7....4....3....0
%e A268456 ..2....0....1....1....6....6....0....6....6....1....6....6....7....4....2....4
%Y A268456 Cf. A268457.
%K A268456 nonn
%O A268456 1,1
%A A268456 _R. H. Hardin_, Feb 04 2016