A203391 Number of nX2 0..3 arrays with every nonzero element less than or equal to some NW, E or S neighbor

1, 16, 185, 1455, 10804, 83876, 661595, 5187181, 40522052, 316707721, 2476929279, 19371658984, 151484525968, 1184573677051, 9263247815357, 72438024528140, 566459469153425, 4429661481889999, 34639556932938188, 270878300837545724

Offset

1,2

Comments

Column 2 of A203397

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 16*a(n-1) -100*a(n-2) +400*a(n-3) -1164*a(n-4) +2172*a(n-5) -2624*a(n-6) +2393*a(n-7) -1552*a(n-8) +736*a(n-9) -324*a(n-10)

Example

Some solutions for n=4
..2..2....1..0....2..3....2..0....1..0....3..1....1..0....1..1....0..3....2..2
..0..2....2..0....1..3....2..2....1..0....3..3....2..0....0..2....0..3....1..2
..3..3....3..0....3..3....1..1....1..0....0..1....2..2....2..2....3..3....0..0
..0..3....3..3....0..3....0..0....1..1....0..0....1..1....0..2....3..3....0..0

Crossrefs

Sequence in context: A016298 A288720 A125428 * A016249 A021049 A067308

Adjacent sequences: A203388 A203389 A203390 * A203392 A203393 A203394

Keyword

nonn

Author

R. H. Hardin Jan 01 2012

Status

approved