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A203185
Number of n X 2 0..4 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.
1
5, 165, 3209, 53233, 904175, 15703631, 271942421, 4694586685, 81072693659, 1400687275175, 24198485401075, 418031304578759, 7221573611135109, 124755169399163453, 2155187028114381493, 37231528687477204117
OFFSET
1,1
COMMENTS
Column 2 of A203191.
LINKS
FORMULA
Empirical: a(n) = 15*a(n-1) -15*a(n-2) +821*a(n-3) +1430*a(n-4) +9500*a(n-5) +11557*a(n-6) +27197*a(n-7) +15316*a(n-8) +14400*a(n-9).
EXAMPLE
Some solutions for n=4
..0..3....4..3....3..3....3..2....2..1....0..4....4..1....1..3....0..3....4..3
..4..3....4..0....2..0....3..1....2..2....0..4....4..3....1..4....3..3....4..0
..4..2....0..4....0..0....2..2....0..0....3..4....4..2....1..4....4..4....1..2
..2..0....0..4....2..2....4..4....0..0....3..0....4..4....2..2....0..0....4..4
CROSSREFS
Cf. A203191.
Sequence in context: A316646 A316174 A317456 * A129995 A259613 A047940
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 30 2011
STATUS
approved