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A258552 Number of (n+1) X (6+1) 0..1 arrays with every 2 X 2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically. 1

%I

%S 988,683,1917,3314,6662,10854,16942,24300,33844,45166,59274,75580,

%T 95044,117306,143422,172852,206604,244366,287242,334740,387916,446506,

%U 511662,582940,661444,746958,840682,942220,1052724,1172026,1301374,1440420

%N Number of (n+1) X (6+1) 0..1 arrays with every 2 X 2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically.

%H R. H. Hardin, <a href="/A258552/b258552.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - 4*a(n-5) + 6*a(n-6) - 4*a(n-7) + a(n-8) for n>14.

%F Empirical g.f.: x*(988 - 3269*x + 5113*x^2 - 4208*x^3 + 2176*x^4 + 374*x^5 - 2954*x^6 + 2530*x^7 - 1622*x^8 + 1571*x^9 - 743*x^10 + 82*x^11 + 6*x^12 + 4*x^13) / ((1 - x)^5*(1 + x)*(1 + x^2)). - _Colin Barker_, Dec 22 2018

%e Some solutions for n=4:

%e ..0..0..0..0..0..0..1....0..0..0..0..0..0..1....1..0..0..0..0..0..1

%e ..0..0..0..0..0..1..1....1..0..0..0..0..0..0....1..0..0..0..0..0..0

%e ..1..1..0..0..1..1..1....1..0..0..0..0..0..0....0..0..0..0..0..0..1

%e ..1..0..0..1..1..1..1....1..0..0..0..0..0..1....1..1..1..1..1..1..1

%e ..1..0..1..1..1..1..1....0..0..0..0..0..0..1....1..1..1..1..0..0..1

%Y Column 6 of A258554.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jun 03 2015

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Last modified October 16 06:14 EDT 2021. Contains 348040 sequences. (Running on oeis4.)