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 A252253 Number of (n+2) X (7+2) 0..3 arrays with every 3 X 3 subblock row and column sum not equal to 0 3 5 6 or 7 and every 3 X 3 diagonal and antidiagonal sum equal to 0 3 5 6 or 7. 1

%I

%S 847,437,366,384,414,453,501,579,681,807,1011,1278,1608,2142,2841,

%T 3705,5103,6933,9195,12855,17646,23568,33150,45693,61197,86283,119121,

%U 159711,225387,311358,417624,589566,814641,1092849,1542999,2132253,2860611

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

%H R. H. Hardin, <a href="/A252253/b252253.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) + 3*a(n-3) - 3*a(n-4) - a(n-6) + a(n-7) for n>9.

%F Empirical g.f.: x*(847 - 410*x - 71*x^2 - 2523*x^3 + 1260*x^4 + 252*x^5 + 841*x^6 - 422*x^7 - 86*x^8) / ((1 - x)*(1 - 3*x^3 + x^6)). - _Colin Barker_, Dec 03 2018

%e Some solutions for n=4:

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

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

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

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

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

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

%Y Column 7 of A252254.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 16 2014

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Last modified November 28 22:15 EST 2021. Contains 349415 sequences. (Running on oeis4.)