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Number of (7+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 15:31:58

%S 5496,4905,7492,10626,20910,33862,48579,104334,172130,244167,588270,

%T 986138,1389063,3730350,6337034,8869479,25958190,44510186,62011047,

%U 192163374,331380650,460363047,1475370030,2552327978,3540109863

%N Number of (7+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 7 of A252305

%H R. H. Hardin, <a href="/A252312/b252312.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 15*a(n-3) -70*a(n-6) +120*a(n-9) -64*a(n-12) for n>19

%e Some solutions for n=4

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

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

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

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 16 2014