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%I #6 Feb 24 2024 08:44:06
%S 1280,7552,45504,300576,1989792,13448144,90873216,619311968,
%T 4216944960,28740190112,195754182912,1336638450880,9119759264640,
%U 62187152129600,423811971529728,2894195784272640,19749810069474816,134677433485842176
%N Number of (n+1) X (2+1) 0..3 arrays with the maximum plus the upper median plus the lower median plus the minimum of every 2 X 2 subblock differing from its horizontal and vertical neighbors by exactly one.
%C Column 2 of A237956.
%H R. H. Hardin, <a href="/A237953/b237953.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2748*a(n-4) -1387988*a(n-8) +288215016*a(n-12) -28573068288*a(n-16) +1342200998400*a(n-20) -26806577111808*a(n-24) +258758317983744*a(n-28) -1294957173878784*a(n-32) +3352065764917248*a(n-36) -4028458590535680*a(n-40) +1526567264059392*a(n-44) for n>46.
%e Some solutions for n=3
%e ..2..2..0....2..0..2....0..1..2....2..3..2....2..1..2....1..1..2....1..2..3
%e ..2..2..3....1..1..2....1..2..0....3..3..2....1..3..0....3..0..3....2..2..1
%e ..3..0..3....0..3..0....2..0..2....1..3..1....2..2..2....0..3..1....1..3..1
%e ..2..1..3....3..0..2....1..3..0....3..2..2....1..2..0....2..0..2....3..2..2
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 16 2014
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