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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

36, 2436, 162776, 10937316, 734979136, 49393306556, 3319433387656, 223079838087956, 14991902921730896, 1007518927448282476, 67709509526621985176, 4550363827896811116996, 305803588199889010224736

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OFFSET

1,1

COMMENTS

Column 2 of A198642

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

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

Adjacent sequences: A198636 A198637 A198638 * A198640 A198641 A198642

KEYWORD

nonn

AUTHOR

R. H. Hardin Oct 27 2011

STATUS

approved