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Number of (n+2)X(7+2) 0..3 arrays with every 3X3 subblock row and column sum not 2 4 5 or 7 and every diagonal and antidiagonal sum 2 4 5 or 7
1

%I #4 Dec 10 2014 09:19:23

%S 32372,99808,40816,62720,267872,506656,893120,3499888,8000000,

%T 15317248,56450688,146923792,294439232,1049159568,2916709968,

%U 5965120064,20941831888,59901392016,123522690880,431054317328,1247133093840

%N Number of (n+2)X(7+2) 0..3 arrays with every 3X3 subblock row and column sum not 2 4 5 or 7 and every diagonal and antidiagonal sum 2 4 5 or 7

%C Column 7 of A251876

%H R. H. Hardin, <a href="/A251875/b251875.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 29*a(n-3) -168*a(n-6) for n>17

%e Some solutions for n=4

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 10 2014