A199094 Number of nX1 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 two or fewer horizontal or vertical neighbors

1, 1, 1, 6, 15, 15, 105, 280, 280, 2100, 5775, 5775, 45045, 126126, 126126, 1009008, 2858856, 2858856, 23279256, 66512160, 66512160, 548725320, 1577585295, 1577585295, 13146544125, 37978905250, 37978905250, 319022804100

Offset

1,4

Comments

Column 1 of A199101

Links

R. H. Hardin, Table of n, a(n) for n = 1..192

Example

Some solutions for n=7
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....1....0....1....1....1....1....1....1....1....1....1....1....1....1....0
..2....1....1....0....2....1....1....2....1....0....2....1....0....0....0....1
..1....2....2....1....2....1....2....2....0....2....0....0....1....2....2....0
..1....0....2....2....1....2....1....1....2....1....2....1....1....2....1....2
..2....2....2....1....0....0....0....0....2....2....0....2....2....1....0....1
..0....0....1....2....1....2....2....2....0....1....1....2....2....0....2....2

Crossrefs

Sequence in context: A200902 A205132 A199223 * A009579 A358760 A114812

Adjacent sequences: A199091 A199092 A199093 * A199095 A199096 A199097

Keyword

nonn

Author

R. H. Hardin Nov 02 2011

Status

approved