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Number of (n+1)X(1+1) 0..3 arrays with the difference between each 2X2 subblock maximum and minimum lexicographically nondecreasing rowwise and columnwise
2

%I #5 Jan 10 2014 08:00:21

%S 256,3038,33610,344668,3402366,32542312,304784986,2807381170,

%T 25538118636,230002990420,2055091563588,18243652764916,

%U 161094988392244,1416214588819266,12404115758918922,108303485972137448

%N Number of (n+1)X(1+1) 0..3 arrays with the difference between each 2X2 subblock maximum and minimum lexicographically nondecreasing rowwise and columnwise

%C Column 1 of A235430

%H R. H. Hardin, <a href="/A235426/b235426.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 15*a(n-1) -17*a(n-2) -518*a(n-3) +1159*a(n-4) +5713*a(n-5) -11569*a(n-6) -22194*a(n-7) +35356*a(n-8) +29720*a(n-9) -34208*a(n-10) -11136*a(n-11) +7680*a(n-12)

%e Some solutions for n=3

%e ..2..2....3..2....0..1....2..1....1..2....2..2....3..0....3..3....0..1....3..3

%e ..1..2....0..1....0..0....2..0....2..2....1..2....3..2....2..3....1..3....2..3

%e ..1..1....3..1....0..1....3..0....2..0....0..3....0..0....0..1....1..0....2..1

%e ..2..1....0..3....3..0....0..0....0..1....1..3....3..1....3..1....3..0....3..1

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 10 2014