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%I #11 Mar 19 2018 22:09:07
%S 104,669,3927,22119,120233,637948,3321772,17052553,86573591,435717423,
%T 2177845221,10825761528,53576004128,264200974309,1299108852679,
%U 6372932446759,31203614429489,152543921033076,744788303718996
%N Number of (1+1) X (n+1) 0..3 arrays with nondecreasing x(i,j)+x(i,j-1) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.
%C Row 1 of A250676.
%H R. H. Hardin, <a href="/A250677/b250677.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 10*a(n-1) - 21*a(n-2) - 54*a(n-3) + 155*a(n-4) + 118*a(n-5) - 228*a(n-6) - 144*a(n-7).
%F Empirical g.f.: x*(104 - 371*x - 579*x^2 + 2514*x^3 + 1516*x^4 - 3792*x^5 - 2304*x^6) / ((1 - 4*x)*(1 - x - x^2)*(1 - 2*x - 4*x^2)*(1 - 3*x - 9*x^2)). - _Colin Barker_, Mar 19 2018
%e Some solutions for n=4:
%e 2 1 3 1 1 1 2 1 0 1 1 2 2 0 0 1 1 1 1 3
%e 3 2 2 3 3 1 3 2 1 2 2 3 1 1 1 1 2 3 3 1
%Y Cf. A250676.
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 26 2014
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