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%I #9 Dec 18 2015 18:17:32
%S 1,24,4080,4890528,41325395328,2461751303097216,
%T 1033802803683039013248,3060537246479645213149335744,
%U 63873994081842807211176279381955968,9397599222467284962086636818784583099209472
%N 1/3 the number of n X n 0..2 arrays with no element equal both to the element above and to the element to its left
%C Diagonal of A184694
%H R. H. Hardin, <a href="/A184687/b184687.txt">Table of n, a(n) for n = 1..11</a>
%e Some solutions for 3X3 with a(1,1)=0
%e ..0..0..1....0..0..1....0..2..1....0..1..1....0..1..2....0..0..0....0..2..0
%e ..1..0..0....0..1..0....2..1..0....2..1..2....0..2..1....2..2..1....0..2..0
%e ..0..2..0....2..2..2....0..2..0....0..1..0....1..1..2....1..0..2....0..1..0
%K nonn
%O 1,2
%A _R. H. Hardin_ Jan 20 2011
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