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%I #8 Dec 11 2018 08:59:59
%S 47,173,724,3160,13810,60368,263920,1153880,5044984,22057880,96442840,
%T 421674392,1843677400,8061072920,35245271896,154102230680,
%U 673778278360,2945948129048,12880513877080,56317230045080,246234772676824
%N Number of (2+1) X (n+1) 0..1 arrays with every 2 X 2 subblock diagonal maximum minus antidiagonal maximum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.
%H R. H. Hardin, <a href="/A253351/b253351.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 5*a(n-1) - 12*a(n-3) for n>6.
%F Empirical g.f.: x*(47 - 62*x - 141*x^2 + 104*x^3 + 86*x^4 + 6*x^5) / ((1 - 2*x)*(1 - 3*x - 6*x^2)). - _Colin Barker_, Dec 11 2018
%e Some solutions for n=4:
%e ..0..1..1..1..0....1..1..0..0..1....0..1..0..0..1....0..1..0..1..0
%e ..0..0..1..1..0....1..1..1..1..1....0..1..0..0..1....1..1..0..1..0
%e ..0..0..1..0..0....1..0..1..1..1....0..1..1..1..1....0..1..0..1..1
%Y Row 2 of A253350.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 30 2014
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