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A252311
Number of (6+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 1 3 6 or 7
1
3681, 3476, 5416, 7489, 14515, 24076, 34279, 70643, 120328, 173799, 386803, 679072, 998407, 2392371, 4310288, 6431079, 16347187, 30013936, 45246631, 119642163, 222278576, 337209639, 912658483, 1706977072, 2598711847, 7123476531
OFFSET
1,1
COMMENTS
Row 6 of A252305
LINKS
FORMULA
Empirical: a(n) = 15*a(n-3) -70*a(n-6) +120*a(n-9) -64*a(n-12) for n>21
EXAMPLE
Some solutions for n=4
..0..0..0..0..3..0....0..3..0..3..0..0....3..3..1..3..3..1....1..1..1..1..1..1
..0..2..1..0..2..1....0..2..1..3..2..1....3..2..2..3..2..2....1..0..2..1..0..2
..2..3..1..2..3..1....2..0..1..2..0..1....2..3..2..2..3..2....3..1..2..3..1..2
..0..3..0..0..3..0....3..0..0..3..0..0....3..3..0..3..3..0....1..1..1..1..1..1
..0..2..1..0..2..1....3..2..1..3..2..1....3..2..2..3..2..2....1..0..2..1..0..2
..2..3..1..2..0..1....2..0..1..2..3..1....2..3..2..2..3..2....3..1..2..3..1..2
..0..3..0..3..0..0....3..0..0..0..3..0....3..3..0..3..3..1....1..1..1..1..1..1
..0..2..1..3..2..1....3..2..1..0..2..1....3..2..2..3..2..1....1..0..2..1..0..2
CROSSREFS
Sequence in context: A103608 A204757 A250875 * A263814 A179130 A234486
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 16 2014
STATUS
approved