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A233226 Number of nX4 0..5 arrays with no element x(i,j) adjacent to value 5-x(i,j) horizontally, diagonally, antidiagonally or vertically, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order.

%I A233226 #6 Jul 23 2025 07:56:50
%S A233226 23,2541,420948,72049266,12389989684,2131764323784,366805442634477,
%T A233226 63115455429961173,10860156414181066717,1868686679256045815893,
%U A233226 321541405170806242604768,55327025424814353393541818
%N A233226 Number of nX4 0..5 arrays with no element x(i,j) adjacent to value 5-x(i,j) horizontally, diagonally, antidiagonally or vertically, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order.
%C A233226 Column 4 of A233230
%H A233226 R. H. Hardin, <a href="/A233226/b233226.txt">Table of n, a(n) for n = 1..210</a>
%F A233226 Empirical: a(n) = 208*a(n-1) -6194*a(n-2) -6657*a(n-3) +1510366*a(n-4) -4909922*a(n-5) -83197258*a(n-6) +434631988*a(n-7) +327946201*a(n-8) -4201117068*a(n-9) +1899947531*a(n-10) +14849526767*a(n-11) -12775127323*a(n-12) -22240589415*a(n-13) +23935227067*a(n-14) +13900628187*a(n-15) -18073202257*a(n-16) -2644553309*a(n-17) +5223316598*a(n-18) -76874653*a(n-19) -517583738*a(n-20) +40060322*a(n-21) +4525360*a(n-22) -152800*a(n-23)
%e A233226 Some solutions for n=2
%e A233226 ..0..0..0..0....0..0..1..1....0..1..2..0....0..0..0..1....0..0..1..2
%e A233226 ..1..0..1..0....1..1..2..5....1..1..1..2....4..4..2..2....2..2..1..5
%K A233226 nonn
%O A233226 1,1
%A A233226 _R. H. Hardin_, Dec 06 2013