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A233261 Number of 6Xn 0..5 arrays with no element x(i,j) adjacent to itself or value 5-x(i,j) horizontally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order (unlabeled 6-colorings with no clashing color pairs).

%I A233261 #8 Sep 25 2024 01:48:41
%S A233261 1248,524800,509640704,495341010944,507618560835584,
%T A233261 525597937107992576,548491734506604068864,573981067569027897884672,
%U A233261 601558225688924228943872000,630830989777808716060719841280
%N A233261 Number of 6Xn 0..5 arrays with no element x(i,j) adjacent to itself or value 5-x(i,j) horizontally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order (unlabeled 6-colorings with no clashing color pairs).
%C A233261 Row 6 of A233256
%H A233261 R. H. Hardin, <a href="/A233261/b233261.txt">Table of n, a(n) for n = 1..210</a>
%F A233261 Empirical: a(n) = 1984*a(n-1) -1282048*a(n-2) +346292224*a(n-3) -27028094976*a(n-4) -6584184864768*a(n-5) +1907721393668096*a(n-6) -214149680718675968*a(n-7) +12624715655426342912*a(n-8) -384499321786383466496*a(n-9) +4759259971017064316928*a(n-10) for n>16
%e A233261 Some solutions for n=2
%e A233261 ..0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1
%e A233261 ..0..1....0..2....0..2....0..2....0..2....0..2....0..1....0..2....0..2....0..2
%e A233261 ..2..4....4..5....1..0....1..5....5..3....1..5....5..1....0..1....4..5....4..0
%e A233261 ..2..0....3..1....3..0....1..2....0..1....1..3....2..4....3..0....2..5....3..5
%e A233261 ..1..0....3..0....4..0....0..2....3..0....5..2....3..1....4..5....4..2....4..5
%e A233261 ..1..3....4..5....4..3....4..2....1..3....4..0....2..4....1..0....1..0....1..5
%K A233261 nonn
%O A233261 1,1
%A A233261 _R. H. Hardin_, Dec 06 2013