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 A252025 Number of (n+2)X(1+2) 0..2 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 2 or 4 1

%I

%S 213,227,357,809,1805,4259,10251,24331,57385,135913,322129,763095,

%T 1807991,4283219,10146569,24037921,56947673,134911263,319611383,

%U 757175635,1793784697,4249564025,10067427977,23850227423,56502354463

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

%C Column 1 of A252032

%H R. H. Hardin, <a href="/A252025/b252025.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) -a(n-2) +5*a(n-3) -2*a(n-4) +3*a(n-5) -2*a(n-6) -2*a(n-7) -2*a(n-8) -2*a(n-9) +2*a(n-11) for n>14

%e Some solutions for n=4

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

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

%e ..2..2..1....2..2..1....2..2..2....2..2..2....2..2..2....2..2..2....1..2..2

%e ..2..2..2....2..2..2....1..2..2....2..2..1....2..2..1....2..1..2....2..2..1

%e ..2..2..2....2..2..2....2..1..2....2..1..2....2..1..2....2..2..2....2..2..2

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 12 2014

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Last modified November 30 08:19 EST 2021. Contains 349419 sequences. (Running on oeis4.)