A199516 - OEIS

A199516

Number of nX1 0..3 arrays with values 0..3 introduced in row major order, the number of instances of each value within one of each other, and every element equal to two or fewer horizontal or vertical neighbors

1, 1, 1, 1, 10, 45, 105, 105, 1260, 6300, 15400, 15400, 200200, 1051050, 2627625, 2627625, 35735700, 192972780, 488864376, 488864376, 6844101264, 37642556952, 96197645544, 96197645544, 1374252079200, 7656547298400, 19688264481600

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

OFFSET

1,5

COMMENTS

Column 1 of A199523

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..174

EXAMPLE

Some solutions for n=6

..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0

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

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