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%I #8 Jan 11 2019 10:44:22
%S 4,64,900,12100,155236,1932100,23444964,278956804,3265665316,
%T 37722185284,430853083236,4874266035076,54692207394724,
%U 609340042214596,6746970728882916,74302629109627396,814375880067172900
%N Number of n X 2 0..3 arrays with every repeated value in every row and column one larger mod 4 than the previous repeated value, and upper left element zero.
%H R. H. Hardin, <a href="/A268165/b268165.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 23*a(n-1) - 106*a(n-2) - 724*a(n-3) + 4128*a(n-4) + 9216*a(n-5) - 20736*a(n-6).
%F Empirical g.f.: 4*x*(1 - 7*x - 37*x^2 + 270*x^3 + 540*x^4 - 1296*x^5) / ((1 + 4*x)*(1 - 9*x)*(1 - 12*x + 16*x^2)*(1 - 6*x - 36*x^2)). - _Colin Barker_, Jan 11 2019
%e Some solutions for n=5:
%e ..0..3....0..2....0..0....0..0....0..1....0..2....0..0....0..0....0..3....0..2
%e ..0..1....3..2....0..2....3..2....0..2....0..0....2..0....1..2....0..3....2..0
%e ..3..1....3..1....2..3....0..1....3..2....3..1....1..1....1..1....1..0....1..0
%e ..0..2....2..3....0..2....0..2....1..3....1..0....2..1....0..2....3..3....1..3
%e ..1..2....1..1....3..1....3..0....2..0....1..0....1..0....2..2....2..0....0..1
%Y Column 2 of A268169.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 27 2016
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