A237854 Number of (n+1)X(3+1) 0..1 arrays with no element greater than all horizontal neighbors or less than all vertical neighbors

7, 41, 184, 773, 3373, 15038, 66838, 295601, 1306735, 5781785, 25589556, 113242992, 501098184, 2217363176, 9812031225, 43419245331, 192134011624, 850208955685, 3762246587434, 16648265214303, 73670007635534, 325996107221214

Offset

1,1

Comments

Column 3 of A237859

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -6*a(n-2) +13*a(n-3) +11*a(n-4) -5*a(n-5) +4*a(n-6) +9*a(n-7) -10*a(n-8) -10*a(n-9) +a(n-11)

Example

Some solutions for n=5
..1..1..1..1....0..0..1..1....0..1..1..1....1..1..1..0....1..1..0..0
..1..1..1..1....0..0..1..1....0..0..0..0....1..1..0..0....1..1..0..0
..1..1..1..0....1..1..1..0....0..0..0..0....1..1..0..0....0..1..1..1
..0..0..0..0....1..1..1..0....0..0..0..0....1..1..0..0....0..0..1..1
..0..0..0..0....0..1..1..1....0..1..1..0....0..0..0..0....0..0..1..1
..1..1..1..0....0..1..1..1....0..1..1..1....0..0..1..1....0..1..1..1

Crossrefs

Sequence in context: A230018 A165563 A034575 * A219862 A366996 A238991

Adjacent sequences: A237851 A237852 A237853 * A237855 A237856 A237857

Keyword

nonn

Author

R. H. Hardin, Feb 14 2014

Status

approved