A198205 - OEIS

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

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