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%I #7 Oct 11 2018 14:08:50
%S 48,188,720,2856,11040,43888,169920,675744,2616960,10407872,40308480,
%T 160311936,620874240,2469299968,9563397120,38034921984,147306178560,
%U 585856596992,2268975329280,9024021866496,34949308784640,138998129717248
%N Number of (n+1) X (1+1) 0..3 arrays with every 2 X 2 subblock having the sum of the squares of all six edge and diagonal differences equal to 11.
%H R. H. Hardin, <a href="/A233785/b233785.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 18*a(n-2) - 40*a(n-4).
%F Empirical g.f.: 4*x*(12 + 47*x - 36*x^2 - 132*x^3) / (1 - 18*x^2 + 40*x^4). - _Colin Barker_, Oct 11 2018
%e Some solutions for n=5:
%e ..2..1....1..2....3..1....2..1....1..2....1..3....0..2....3..2....0..0....2..0
%e ..0..2....2..0....3..2....2..0....0..0....2..1....1..2....1..1....2..1....2..1
%e ..2..1....1..2....3..1....2..1....2..1....1..3....1..3....3..2....3..1....0..0
%e ..1..3....2..0....2..1....3..3....3..1....2..3....2..1....1..3....1..2....2..1
%e ..1..2....1..0....2..0....2..1....2..1....3..1....1..3....1..2....2..0....2..0
%e ..0..2....2..0....1..2....2..0....3..1....2..1....3..2....2..0....1..2....1..2
%Y Column 1 of A233792.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 15 2013
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