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A198639
Number of 2nX4 0..2 arrays with values 0..2 introduced in row major order and each element equal to an even number of horizontal and vertical neighbors
1
36, 2436, 162776, 10937316, 734979136, 49393306556, 3319433387656, 223079838087956, 14991902921730896, 1007518927448282476, 67709509526621985176, 4550363827896811116996, 305803588199889010224736
OFFSET
1,1
COMMENTS
Column 2 of A198642
LINKS
FORMULA
Empirical: a(n) = 78*a(n-1) -569*a(n-2) -11744*a(n-3) +71840*a(n-4) +745984*a(n-5) -2507008*a(n-6) -18538496*a(n-7) +36110336*a(n-8) +142606336*a(n-9) -268435456*a(n-10)
EXAMPLE
Some solutions for n=3
..0..1..0..2....0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1
..1..0..1..0....1..0..1..0....1..0..2..0....1..0..1..0....1..0..2..0
..2..1..2..1....2..2..0..1....2..1..0..1....2..1..0..1....2..1..0..1
..1..2..1..2....2..2..1..0....0..2..1..2....1..2..1..0....1..2..1..2
..2..0..2..0....0..1..2..1....2..1..2..0....0..1..0..2....2..1..0..1
..1..2..0..1....1..0..1..0....0..2..1..2....1..0..2..1....1..2..1..2
CROSSREFS
Sequence in context: A230465 A120466 A202633 * A159728 A268365 A004706
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 27 2011
STATUS
approved