A203185 Number of n X 2 0..4 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.

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

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

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

Adjacent sequences: A203182 A203183 A203184 * A203186 A203187 A203188

Keyword

nonn

Author

R. H. Hardin, Dec 30 2011

Status

approved