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A252258 Number of (n+2) X (2+2) 0..3 arrays with every 3 X 3 subblock row and column sum not equal to 0 2 3 6 or 7 and every 3 X 3 diagonal and antidiagonal sum equal to 0 2 3 6 or 7. 1

%I

%S 1331,1016,562,512,570,782,1178,1670,2474,3890,5642,8594,13922,20498,

%T 31778,52418,77858,121922,203138,303170,477314,799490,1196162,1888514,

%U 3171842,4751618,7512578,12635138,18940418,29967362,50436098,75629570

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

%H R. H. Hardin, <a href="/A252258/b252258.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) + 6*a(n-3) - 6*a(n-4) - 8*a(n-6) + 8*a(n-7) for n>12.

%F Empirical g.f.: x*(1331 - 315*x - 454*x^2 - 8036*x^3 + 1948*x^4 + 2936*x^5 + 11344*x^6 - 2376*x^7 - 4100*x^8 - 1360*x^9 - 736*x^10 - 176*x^11) / ((1 - x)*(1 - 2*x^3)*(1 - 4*x^3)). - _Colin Barker_, Dec 03 2018

%e Some solutions for n=4:

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

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

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

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

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

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

%Y Column 2 of A252260.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 16 2014

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Last modified April 18 22:08 EDT 2019. Contains 322237 sequences. (Running on oeis4.)