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A233127 Number of nX6 0..5 arrays with no element x(i,j) adjacent to itself or value 5-x(i,j) horizontally or vertically, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order (unlabelled 6-colorings with no clashing color pairs).

%I A233127 #6 Jun 02 2025 08:51:02
%S A233127 136,124928,127533056,132682612736,138791062863872,145451790488305664,
%T A233127 152534173898504142848,160000135886807521820672,
%U A233127 167846256915736431983329280,176082743571854371127073701888
%N A233127 Number of nX6 0..5 arrays with no element x(i,j) adjacent to itself or value 5-x(i,j) horizontally or vertically, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order (unlabelled 6-colorings with no clashing color pairs).
%C A233127 Column 6 of A233129
%H A233127 R. H. Hardin, <a href="/A233127/b233127.txt">Table of n, a(n) for n = 1..210</a>
%F A233127 Empirical: a(n) = 1984*a(n-1) -1314816*a(n-2) +411303936*a(n-3) -70111985664*a(n-4) +6893422510080*a(n-5) -389708152569856*a(n-6) +11733988091625472*a(n-7) -145241087982698496*a(n-8)
%e A233127 Some solutions for n=2
%e A233127 ..0..1..2..4..2..0....0..1..2..5..1..5....0..1..0..1..5..2....0..1..0..4..2..1
%e A233127 ..1..5..4..2..0..4....4..2..4..3..5..2....3..5..4..0..4..5....1..5..4..2..4..2
%K A233127 nonn
%O A233127 1,1
%A A233127 _R. H. Hardin_, Dec 04 2013