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Number of n X 7 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).
1

%I #9 Sep 02 2024 19:39:15

%S 528,1992704,8050180096,32835998056448,134179300927602688,

%T 548491734506604068864,2242238966451009797226496,

%U 9166394920089108387649814528,37472795110784044637628292661248

%N Number of n X 7 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 Column 7 of A233256.

%H R. H. Hardin, <a href="/A233255/b233255.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5504*a(n-1) -6438912*a(n-2) +2774532096*a(n-3) -478351982592*a(n-4) +27831388078080*a(n-5).

%e Some solutions for n=2

%e ..0..1..0..1..2..5..2....0..1..0..1..0..2..4....0..1..0..1..2..4..3

%e ..5..1..3..5..3..4..3....2..4..0..3..1..3..5....3..4..0..4..3..0..2

%Y Cf. A233256.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 06 2013