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A258551 Number of (n+1) X (5+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 480,506,1403,2509,5070,8339,12940,18630,26240,35386,46687,59945,

%T 76039,94633,116394,141172,169894,202272,239021,280039,326301,377567,

%U 434600,497346,566828,642854,726235,816965,916115,1023541,1140102,1265840

%N Number of (n+1) X (5+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="/A258551/b258551.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>13.

%F Empirical g.f.: x*(480 - 1414*x + 2259*x^2 - 1987*x^3 + 1428*x^4 - 579*x^5 - 888*x^6 + 1120*x^7 - 834*x^8 + 778*x^9 - 368*x^10 + 50*x^11 + 3*x^12) / ((1 - x)^5*(1 + x)*(1 + x^2)). - _Colin Barker_, Dec 21 2018

%e Some solutions for n=4:

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

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

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

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

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

%Y Column 5 of A258554.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jun 03 2015

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Last modified September 26 20:34 EDT 2021. Contains 347672 sequences. (Running on oeis4.)