Voozh

A199242

Number of nX4 0..2 arrays with values 0..2 introduced in row major order, the number of instances of each value within one of each other, and every element equal to zero or two horizontal or vertical neighbors.

3, 12, 25, 440, 2907, 7100, 134821, 934004, 2277108, 46296108, 330908530, 820702285, 17258404593, 125752465794, 315014793177, 6765057712760, 49918706666467, 125910537922412, 2743415189299833, 20425391744058298

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

OFFSET

1,1

COMMENTS

Column 4 of A199246

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..30

EXAMPLE

Some solutions for n=5

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

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

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