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A198205 Number of 2nX2 0..3 arrays with values 0..3 introduced in row major order and each element unequal to exactly two horizontal and vertical neighbors 1
4, 43, 658, 11029, 189376, 3272959, 56665678, 981535273, 17003856124, 294580477651, 5103458162314, 88415060881213, 1531751228239288, 26536907089886119, 459740106490112326, 7964792868501695569 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A198209

LINKS

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

FORMULA

Empirical: a(n) = 23*a(n-1) -103*a(n-2) +81*a(n-3)

EXAMPLE

Some solutions for n=3

..0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1

..2..2....2..3....2..2....2..0....1..2....2..2....2..2....2..3....2..0....2..2

..1..1....2..3....1..1....2..0....1..2....0..0....3..3....2..3....2..0....0..1

..0..0....3..1....0..2....0..3....0..1....3..2....2..2....0..2....0..3....0..1

..1..1....3..1....0..2....0..3....0..1....3..2....1..1....0..2....0..3....2..2

..3..2....2..3....3..0....3..1....1..3....0..1....3..0....1..0....3..0....1..0

CROSSREFS

Sequence in context: A186768 A130545 A027311 * A277639 A326432 A074702

Adjacent sequences:  A198202 A198203 A198204 * A198206 A198207 A198208

KEYWORD

nonn

AUTHOR

R. H. Hardin Oct 22 2011

STATUS

approved

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Last modified January 18 02:50 EST 2022. Contains 350410 sequences. (Running on oeis4.)