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

%I #4 Dec 19 2014 11:30:37

%S 1758,4026,12840,39492,145594,527688,1812508,7013991,27089549,

%T 99843027,396169255,1576927259,6006620761,24092395312,97158953094,

%U 375234161454,1511433556881,6126979242693,23792634809473,95990057129897

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

%C Column 3 of A252640

%H R. H. Hardin, <a href="/A252635/b252635.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 140*a(n-3) -6944*a(n-6) +157621*a(n-9) -1691268*a(n-12) +8267548*a(n-15) -25478928*a(n-18) +65654144*a(n-21) -110095616*a(n-24) +126170112*a(n-27) -143638528*a(n-30) +78643200*a(n-33) for n>42

%e Some solutions for n=4

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 19 2014