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A207277
Number of n X 2 0..3 arrays avoiding the patterns z z+1 z or z z-1 z in any row, column, diagonal or antidiagonal.
3
16, 256, 3364, 45796, 620944, 8421604, 114190596, 1548422500, 20996589604, 284714019396, 3860721976384, 52351389401476, 709884831344896, 9626038324365376, 130529079640391056, 1769974318948977124
OFFSET
1,1
COMMENTS
Column 2 of A207283.
LINKS
FORMULA
Empirical: a(n) = 11*a(n-1) +28*a(n-2) +48*a(n-3) +536*a(n-4) +664*a(n-5) -205*a(n-6) -656*a(n-7) -535*a(n-8) +4*a(n-9) +212*a(n-10) +175*a(n-11) -36*a(n-12) +5*a(n-13) -8*a(n-14) +a(n-15).
a(n) = A207276(n)^2. - Mark van Hoeij, May 14 2013
EXAMPLE
Some solutions for n=4
..2..3....1..0....2..3....2..2....2..2....3..1....2..0....1..3....3..3....0..0
..3..0....1..3....3..0....1..0....1..0....1..2....1..0....2..1....0..1....3..0
..1..2....1..3....0..2....0..3....3..2....0..2....3..0....2..1....0..0....1..1
..3..2....3..1....1..3....0..0....2..0....0..0....1..2....0..3....3..2....2..1
CROSSREFS
Sequence in context: A223660 A223565 A223677 * A294329 A267929 A122609
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 16 2012
STATUS
approved