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Number of (n+1)X(n+1) 0..7 arrays with every 2X2 subblock commuting with each of its horizontal and vertical 2X2 subblock neighbors
1

%I #6 Mar 31 2012 12:36:05

%S 4096,4834,269126,1024481,21122896,70300633,1381305433,5019710665,

%T 92758821369,358905890921,6225263778969,25517863738777,

%U 418350075763113,1809120677086713,28157232600156937,127921801557860825

%N Number of (n+1)X(n+1) 0..7 arrays with every 2X2 subblock commuting with each of its horizontal and vertical 2X2 subblock neighbors

%C Diagonal of A186490

%H R. H. Hardin, <a href="/A186489/b186489.txt">Table of n, a(n) for n = 1..20</a>

%e Some solutions for 3X3

%e ..6..0..6....7..4..0....3..6..3....3..5..0....6..7..0....5..4..0....5..0..0

%e ..0..6..0....1..0..4....6..3..6....1..0..5....5..0..7....0..0..4....0..0..0

%e ..3..0..6....0..1..5....3..6..3....0..1..4....0..5..7....0..0..3....0..0..0

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 22 2011