A205304 - OEIS

A205304

Number of n X n 0..3 arrays with no occurrence of three equal elements in a row horizontally or vertically, and new values 0..3 introduced in row major order.

1, 15, 7445, 70985206, 8615950028840, 13585407518869992739

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..6.

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Diagonal of A205310.

Sequence in context: A205155 A208095 A271402 * A334835 A206295 A074488

Adjacent sequences: A205301 A205302 A205303 * A205305 A205306 A205307

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 25 2012

STATUS

approved