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A274955
Number of nX4 0..2 arrays with no element equal to any value at offset (-1,-1) (-2,0) or (0,-2) and new values introduced in order 0..2.
1
6, 72, 384, 2376, 14406, 87780, 536406, 3278016, 20027574, 122367012, 747675414, 4568374272, 27913169094, 170551986900, 1042088376006, 6367256060400, 38904520522614, 237710201714820, 1452431219269686, 8874488478680352
OFFSET
1,1
COMMENTS
Column 4 of A274959.
LINKS
FORMULA
Empirical: a(n) = 6*a(n-1) +4*a(n-3) +13*a(n-4) -74*a(n-5) -8*a(n-6) -4*a(n-8) +8*a(n-9) for n>11
EXAMPLE
Some solutions for n=4
..0..1..1..0. .0..1..1..0. .0..1..1..2. .0..1..1..2. .0..1..1..0
..1..1..2..0. .2..2..0..0. .2..1..0..0. .2..1..0..0. .2..1..0..0
..1..2..0..1. .2..0..0..1. .2..0..0..1. .1..0..0..1. .1..0..0..1
..2..2..0..1. .1..0..2..2. .0..0..1..1. .1..0..2..2. .0..2..2..1
CROSSREFS
Cf. A274959.
Sequence in context: A276244 A361571 A282817 * A177468 A052791 A334327
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 12 2016
STATUS
approved