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A236149
Number of (n+1) X (2+1) 0..2 arrays colored with the sets of distinct values in every 2 X 2 subblock.
1
414, 2502, 16128, 104436, 676980, 4389660, 28462080, 184549536, 1196622156, 7758928296, 50309072208, 326205221604, 2115122387760, 13714503742644, 88925167552200, 576592895708256, 3738642012281784, 24241443486843000
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) + 19*a(n-2) + 24*a(n-3) - a(n-4) - 22*a(n-5) - 11*a(n-6) - 2*a(n-7) - 2*a(n-8).
Empirical g.f.: 6*x*(69 + 210*x + 126*x^2 - 237*x^3 - 399*x^4 - 171*x^5 - 43*x^6 - 27*x^7) / (1 - 3*x - 19*x^2 - 24*x^3 + x^4 + 22*x^5 + 11*x^6 + 2*x^7 + 2*x^8). - Colin Barker, Oct 20 2018
EXAMPLE
Some solutions for n=4:
..1..0..1....0..0..2....2..2..1....0..1..2....0..1..2....0..0..2....0..0..2
..2..1..0....1..1..2....0..0..1....2..2..1....1..2..2....1..1..1....2..2..1
..2..2..2....1..1..2....2..1..0....0..0..0....2..1..0....1..1..0....2..2..1
..2..2..0....1..2..0....1..2..2....0..0..1....0..0..1....1..2..0....2..0..0
..2..1..1....1..0..0....0..2..2....2..2..0....1..0..2....0..2..2....1..2..0
CROSSREFS
Column 2 of A236155.
Sequence in context: A253489 A253496 A253450 * A231312 A210304 A332141
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 19 2014
STATUS
approved