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A183548 Number of nX3 0..2 arrays with each element equal to either the maximum or the minimum of its horizontal and vertical neighbors.

%I A183548 #7 Jul 22 2025 09:05:12
%S A183548 3,71,583,5287,46841,417809,3721925,33169105,295565367,2633809823,
%T A183548 23469955635,209141864227,1863672026457,16607262667561,
%U A183548 147988036529381,1318727810932497,11751240682625031,104715815140064955
%N A183548 Number of nX3 0..2 arrays with each element equal to either the maximum or the minimum of its horizontal and vertical neighbors.
%C A183548 Column 3 of A183554
%H A183548 R. H. Hardin, <a href="/A183548/b183548.txt">Table of n, a(n) for n = 1..200</a>
%F A183548 Empirical: a(n)=12*a(n-1)-26*a(n-2)-33*a(n-3)+204*a(n-4)-244*a(n-5)-339*a(n-6)+256*a(n-7)+1324*a(n-8)-559*a(n-9)-4420*a(n-10)+5965*a(n-11)+8096*a(n-12)-10724*a(n-13)-1370*a(n-14)+5054*a(n-15)-15721*a(n-16)+9505*a(n-17)-7190*a(n-18)-20835*a(n-19)+2723*a(n-20)+1324*a(n-21)+2340*a(n-22)+2496*a(n-23)-1996*a(n-24)-452*a(n-25)+2222*a(n-26)+273*a(n-27)-941*a(n-28)+334*a(n-29)-61*a(n-30)-44*a(n-31)+12*a(n-32)
%e A183548 Some solutions for 5X3
%e A183548 ..2..2..2....0..0..0....1..1..1....2..2..1....0..2..2....1..1..1....0..0..1
%e A183548 ..0..0..0....2..2..0....1..1..1....0..2..1....0..2..1....2..2..0....0..0..1
%e A183548 ..0..2..2....2..0..0....1..1..1....0..0..1....2..2..1....2..2..0....2..2..0
%e A183548 ..2..1..2....0..0..0....0..2..0....0..0..1....2..2..2....2..0..0....0..2..0
%e A183548 ..2..1..1....1..1..0....0..2..0....0..0..1....2..0..0....0..0..0....0..2..2
%K A183548 nonn
%O A183548 1,1
%A A183548 _R. H. Hardin_ Jan 05 2011