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A252580 Number of (6+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 A252580 #6 Jun 02 2025 11:24:34
%S A252580 4583,17261,96099,263046,1887578,11285381,31059674,225598956,
%T A252580 1361132361,3729210396,27362165487,166198069299,453536490301,
%U A252580 3356182671339,20487487055456,55725146612802,415147146187485,2543940816582309
%N A252580 Number of (6+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 A252580 Row 6 of A252574
%H A252580 R. H. Hardin, <a href="/A252580/b252580.txt">Table of n, a(n) for n = 1..210</a>
%F A252580 Empirical: a(n) = 235*a(n-3) -15377*a(n-6) +231134*a(n-9) -2810947*a(n-12) +23472227*a(n-15) -127442070*a(n-18) +618426102*a(n-21) -1174418266*a(n-24) +287094995*a(n-27) +1098948151*a(n-30) -697123678*a(n-33) -202978930*a(n-36) +197586425*a(n-39) -20970000*a(n-42) for n>50
%e A252580 Some solutions for n=3
%e A252580 ..0..2..0..0..1....0..2..0..0..2....1..0..0..2..0....0..2..0..0..2
%e A252580 ..2..2..3..2..2....1..2..3..2..2....0..2..0..0..2....1..2..3..2..2
%e A252580 ..1..0..0..2..0....2..0..0..2..0....2..2..3..1..2....2..0..0..2..0
%e A252580 ..0..1..0..0..2....0..2..0..0..2....2..0..0..2..0....0..2..0..0..1
%e A252580 ..2..2..3..1..1....2..2..3..2..1....0..2..0..0..2....2..2..3..2..2
%e A252580 ..2..0..0..2..0....1..0..0..2..0....1..2..3..2..1....1..0..0..2..0
%e A252580 ..0..2..0..0..2....1..1..0..0..2....2..0..0..2..0....0..2..0..0..1
%e A252580 ..2..2..3..1..1....2..2..3..2..2....1..1..0..0..2....2..2..3..2..2
%K A252580 nonn
%O A252580 1,1
%A A252580 _R. H. Hardin_, Dec 18 2014