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%I #4 Nov 28 2014 19:05:41
%S 413,2812,16208,87529,442409,2130148,9865706,44282475,193738371,
%T 829672404,3489686970,14454185655,59084278573,238768911154,
%U 955319655916,3788887514683,14911360133421,58283593894282,226427164514046
%N Number of (3+1)X(n+1) 0..2 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 3 of A250942
%H R. H. Hardin, <a href="/A250945/b250945.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 12*a(n-1) -38*a(n-2) -76*a(n-3) +619*a(n-4) -500*a(n-5) -2802*a(n-6) +4652*a(n-7) +5756*a(n-8) -14556*a(n-9) -5630*a(n-10) +24440*a(n-11) +1511*a(n-12) -24616*a(n-13) +1882*a(n-14) +15280*a(n-15) -1829*a(n-16) -5700*a(n-17) +596*a(n-18) +1160*a(n-19) -64*a(n-20) -96*a(n-21)
%e Some solutions for n=4
%e ..1..0..2..1..2....2..1..2..0..2....2..0..0..0..2....2..0..0..1..1
%e ..2..1..1..2..1....2..1..2..0..2....2..0..1..1..1....2..0..0..1..1
%e ..2..2..2..1..2....2..1..2..1..1....1..1..0..2..0....1..1..1..2..0
%e ..2..2..2..2..1....2..1..2..1..2....1..1..0..2..2....2..0..2..1..2
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 28 2014