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Number of (n+2)X3 0..2 arrays with every 3X3 subblock having three strictly increasing elements in a row horizontally, vertically or nw-to-se diagonally
1

%I #5 Mar 31 2012 12:37:01

%S 4293,47883,719125,6579664,70193731,852798050,8916413698,96129489898,

%T 1088258363670,11799987759443,128424052872957,1421756480602128,

%U 15554915760569671,170073781922617341,1870112186157878650

%N Number of (n+2)X3 0..2 arrays with every 3X3 subblock having three strictly increasing elements in a row horizontally, vertically or nw-to-se diagonally

%C Column 1 of A204408

%H R. H. Hardin, <a href="/A204401/b204401.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +26*a(n-2) +677*a(n-3) +2185*a(n-4) +4172*a(n-5) +2924*a(n-6) +787*a(n-7) -1302*a(n-8) -864*a(n-9) -324*a(n-10)

%e Some solutions for n=3

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 15 2012