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A221588
Equals one maps: number of n X 3 binary arrays indicating the locations of corresponding elements equal to exactly one of their king-move neighbors in a random 0..3 n X 3 array.
1
4, 40, 418, 3760, 31416, 256736, 2075520, 16690688, 133871616, 1072357376, 8584396800, 68697325568, 549667209216, 4397692092416, 35182954414080, 281469306011648, 2251777130889216, 18014307778297856, 144114825151119360
OFFSET
1,1
COMMENTS
Column 3 of A221590.
LINKS
FORMULA
Empirical: a(n) = 12*a(n-1) -32*a(n-2) for n>6.
Conjectures from Colin Barker, Aug 09 2018: (Start)
G.f.: 2*x*(2 - 4*x + 33*x^2 + 12*x^3 - 164*x^4 + 32*x^5) / ((1 - 4*x)*(1 - 8*x)).
a(n) = 8^n - 169*2^(2*n-7) for n>4.
(End)
EXAMPLE
Some solutions for n=3:
..0..1..0....0..1..0....1..0..1....1..1..1....0..1..0....0..1..0....1..1..1
..0..1..0....0..0..1....1..0..0....0..1..0....1..0..0....0..0..0....1..1..1
..0..1..1....1..1..1....0..1..0....0..0..1....0..1..1....1..1..1....0..1..1
CROSSREFS
Cf. A221590.
Sequence in context: A093141 A220965 A278036 * A114468 A264112 A372460
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 20 2013
STATUS
approved