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A208874
Number of 3Xn 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors
1
5, 143, 6520, 307165, 14493405, 683903931, 32271626438, 1522813452263, 71857577327143, 3390770839381669, 160001593732718856, 7550056082308516761, 356267369073405009281, 16811323900505484274607, 793282337427660173475274
OFFSET
1,1
COMMENTS
Row 3 of A208872
LINKS
FORMULA
Empirical: a(n) = 61*a(n-1) -722*a(n-2) +3476*a(n-3) -7851*a(n-4) +8583*a(n-5) -4266*a(n-6) +720*a(n-7) for n>8
EXAMPLE
Some solutions for n=4
..0..1..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..2..2..1..2....1..1..1..2....1..2..2..1....1..1..1..0....1..1..1..0
..1..2..3..2....2..0..1..3....1..0..1..2....0..0..1..1....2..2..3..2
CROSSREFS
Sequence in context: A066264 A171776 A277401 * A222289 A134503 A282836
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 02 2012
STATUS
approved