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A252578 Number of (4+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 5 6 or 7.

%I A252578 #6 Jun 02 2025 11:24:19
%S A252578 1469,3286,10885,25882,107651,395500,959944,4006901,14816006,35925302,
%T A252578 149837853,555593556,1346798430,5611997409,20856438080,50548611374,
%U A252578 210462210945,783856206336,1899488450222,7902528627913,29493363498624
%N A252578 Number of (4+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 5 6 or 7.
%C A252578 Row 4 of A252574
%H A252578 R. H. Hardin, <a href="/A252578/b252578.txt">Table of n, a(n) for n = 1..210</a>
%F A252578 Empirical: a(n) = 78*a(n-3) -1701*a(n-6) +7656*a(n-9) -30460*a(n-12) +70284*a(n-15) -70416*a(n-18) +25968*a(n-21) -1408*a(n-24) for n>31
%e A252578 Some solutions for n=4
%e A252578 ..2..3..2..1..3..2....0..2..0..0..1..0....0..0..2..0..0..1....0..0..2..0..0..2
%e A252578 ..0..0..2..0..0..2....0..0..1..0..0..1....3..1..2..3..2..2....3..1..2..3..2..1
%e A252578 ..2..0..0..2..0..0....3..2..2..3..2..2....0..2..0..0..1..0....0..2..0..0..2..0
%e A252578 ..2..3..2..2..3..2....0..1..0..0..2..0....0..0..1..0..0..2....0..0..2..0..0..2
%e A252578 ..0..0..1..0..0..2....0..0..2..0..0..2....3..2..2..3..2..1....0..1..1..3..2..1
%e A252578 ..1..0..0..1..0..0....3..2..1..3..1..2....0..1..0..0..2..0....0..2..0..0..2..0
%K A252578 nonn
%O A252578 1,1
%A A252578 _R. H. Hardin_, Dec 18 2014