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%I #7 Jan 15 2022 23:07:20
%S 5,165,3209,53233,904175,15703631,271942421,4694586685,81072693659,
%T 1400687275175,24198485401075,418031304578759,7221573611135109,
%U 124755169399163453,2155187028114381493,37231528687477204117
%N Number of n X 2 0..4 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.
%C Column 2 of A203191.
%H R. H. Hardin, <a href="/A203185/b203185.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 15*a(n-1) -15*a(n-2) +821*a(n-3) +1430*a(n-4) +9500*a(n-5) +11557*a(n-6) +27197*a(n-7) +15316*a(n-8) +14400*a(n-9).
%e Some solutions for n=4
%e ..0..3....4..3....3..3....3..2....2..1....0..4....4..1....1..3....0..3....4..3
%e ..4..3....4..0....2..0....3..1....2..2....0..4....4..3....1..4....3..3....4..0
%e ..4..2....0..4....0..0....2..2....0..0....3..4....4..2....1..4....4..4....1..2
%e ..2..0....0..4....2..2....4..4....0..0....3..0....4..4....2..2....0..0....4..4
%Y Cf. A203191.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 30 2011
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