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Number of (4+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 1 3 6 or 7
1

%I #4 Dec 16 2014 15:30:03

%S 1763,1516,2151,3032,5230,8130,11639,20350,31954,45815,80430,126682,

%T 181895,319918,504586,724967,1276206,2014186,2894759,5098030,8048554,

%U 11568935,20378670,32177962,46255655,81487918,128679466,184982567

%N Number of (4+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 1 3 6 or 7

%C Row 4 of A252305

%H R. H. Hardin, <a href="/A252309/b252309.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 7*a(n-3) -14*a(n-6) +8*a(n-9) for n>15

%e Some solutions for n=4

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 16 2014