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A250689 Number of (n+1)X(6+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.

%I A250689 #6 Jul 23 2025 12:41:50
%S A250689 193117,995624,5098590,25235016,117793753,523260542,2224688673,
%T A250689 9121206688,36332194553,141502429478,541706838601,2047265474206,
%U A250689 7665603013743,28522048068276,105725887121051,391286691949576
%N A250689 Number of (n+1)X(6+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 A250689 Column 6 of A250691
%H A250689 R. H. Hardin, <a href="/A250689/b250689.txt">Table of n, a(n) for n = 1..90</a>
%F A250689 Empirical: a(n) = 27*a(n-1) -331*a(n-2) +2439*a(n-3) -12049*a(n-4) +42129*a(n-5) -107225*a(n-6) +201069*a(n-7) -277706*a(n-8) +278928*a(n-9) -197984*a(n-10) +94032*a(n-11) -26784*a(n-12) +3456*a(n-13) for n>17
%e A250689 Some solutions for n=1
%e A250689 ..2..2..3..2..1..1..0....0..0..0..1..0..1..0....0..0..0..1..0..1..1
%e A250689 ..2..2..3..3..3..3..3....2..2..2..3..2..3..2....0..0..0..2..1..3..3
%K A250689 nonn
%O A250689 1,1
%A A250689 _R. H. Hardin_, Nov 26 2014