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A258559 Number of (6+1) X (n+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 988,2530,3980,6196,8339,10854,13833,17058,20414,23858,27446,31237,

%T 35188,39256,43497,47970,52632,57440,62450,67721,73210,78874,84769,

%U 90954,97386,104022,110918,118133,125624,133348,141361,149722,158388,167316,176562

%N Number of (6+1) X (n+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="/A258559/b258559.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) + a(n-4) - 3*a(n-5) + 3*a(n-6) - a(n-7) for n>13.

%F Empirical g.f.: x*(988 - 434*x - 646*x^2 + 858*x^3 - 1827*x^4 + 879*x^5 + 738*x^6 - 1076*x^7 + 724*x^8 - 488*x^9 - 36*x^10 + 277*x^11 + 72*x^12) / ((1 - x)^4*(1 + x)*(1 + x^2)). - _Colin Barker_, Dec 22 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

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

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

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

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

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

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

%Y Row 6 of A258554.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jun 03 2015

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Last modified October 23 14:42 EDT 2021. Contains 348214 sequences. (Running on oeis4.)