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A250733 Number of (4+1) X (n+1) 0..1 arrays with nondecreasing x(i,j)+x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.

%I A250733 #8 Nov 16 2018 11:16:33
%S A250733 58,144,365,885,2092,4889,11377,26419,61330,142336,330417,767047,
%T A250733 1781019,4135537,9603827,22303104,51797791,120298572,279397140,
%U A250733 648909915,1507137312,3500429630,8130041844,18882699707,43856786967,101861340070
%N A250733 Number of (4+1) X (n+1) 0..1 arrays with nondecreasing x(i,j)+x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.
%H A250733 R. H. Hardin, <a href="/A250733/b250733.txt">Table of n, a(n) for n = 1..210</a>
%F A250733 Empirical: a(n) = 4*a(n-1) - a(n-2) - 13*a(n-3) + 15*a(n-4) + 3*a(n-5) - 11*a(n-6) + 4*a(n-7) for n>9.
%F A250733 Empirical g.f.: x*(58 - 88*x - 153*x^2 + 323*x^3 - 81*x^4 - 183*x^5 + 149*x^6 - 22*x^7 - 8*x^8) / ((1 - x)^2*(1 - 2*x - 4*x^2 + 7*x^3 + 3*x^4 - 4*x^5)). - _Colin Barker_, Nov 16 2018
%e A250733 Some solutions for n=4:
%e A250733 ..0..0..0..0..0....0..0..0..0..1....0..0..0..0..0....0..0..0..0..0
%e A250733 ..0..0..0..0..0....0..0..0..0..1....0..0..0..0..0....0..0..0..0..0
%e A250733 ..0..0..0..0..0....0..0..0..0..1....0..0..0..0..1....0..0..0..1..1
%e A250733 ..1..0..0..0..1....1..0..1..1..1....0..0..0..1..0....0..0..1..1..1
%e A250733 ..0..1..1..1..0....0..1..1..1..1....0..0..1..0..1....0..1..1..1..1
%Y A250733 Row 4 of A250729.
%K A250733 nonn
%O A250733 1,1
%A A250733 _R. H. Hardin_, Nov 27 2014