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A203391
Number of nX2 0..3 arrays with every nonzero element less than or equal to some NW, E or S neighbor
1
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
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
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 01 2012
STATUS
approved