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A222836
Number of nX6 0..3 arrays with no element equal to another at a city block distance of exactly two, and new values 0..3 introduced in row major order
1
55, 1536, 1944, 4056, 9600, 24576, 55296, 124416, 279936, 645504, 1476096, 3393024, 7742976, 17750400, 40560000, 92952576, 212557824, 486864384, 1113680256, 2550116736, 5834651136, 13357979136, 30567200256, 69973632384, 160134620544
OFFSET
1,1
COMMENTS
Column 6 of A222838
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +2*a(n-2) -4*a(n-3) +4*a(n-4) -4*a(n-5) +2*a(n-6) -6*a(n-7) +a(n-10) for n>14
EXAMPLE
Some solutions for n=4
..0..1..2..2..3..0....0..1..1..2..0..3....0..1..2..2..1..3....0..1..2..0..3..1
..0..3..3..0..1..1....0..2..3..3..1..2....0..1..3..3..0..0....2..1..3..0..2..2
..2..2..1..0..2..3....1..2..0..0..1..2....3..2..0..1..2..2....2..0..3..1..1..3
..3..0..1..3..2..0....3..3..1..2..3..3....3..2..0..1..3..3....3..0..2..2..0..0
CROSSREFS
Sequence in context: A017771 A322502 A271796 * A017718 A173113 A166844
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 06 2013
STATUS
approved