A231657 Number of nX2 0..2 arrays with no element less than a strict majority of its horizontal, vertical and antidiagonal neighbors

3, 15, 93, 458, 2163, 10789, 53813, 265397, 1311447, 6493700, 32130833, 158937397, 786355013, 3890673454, 19249161646, 95235762295, 471186213619, 2331226488364, 11533889645847, 57064690337149, 282331462742945, 1396854097460108

Offset

1,1

Comments

Column 2 of A231663

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -28*a(n-2) +65*a(n-3) -167*a(n-4) +235*a(n-5) -237*a(n-6) +327*a(n-7) -345*a(n-8) +267*a(n-9) -198*a(n-10) +193*a(n-11) -88*a(n-12) +52*a(n-13) -20*a(n-14) +16*a(n-15)

Example

Some solutions for n=7
..2..0....1..0....0..0....0..2....0..0....1..1....0..0....0..0....0..0....2..2
..0..0....0..0....2..0....0..0....1..0....1..2....0..2....0..0....1..0....2..0
..2..1....0..2....1..0....0..1....2..0....1..2....1..1....0..1....0..1....0..0
..1..1....0..1....0..0....2..2....0..1....1..1....1..1....1..0....0..0....2..0
..2..1....0..0....2..2....2..0....0..0....2..1....2..1....0..0....0..2....0..0
..0..0....0..1....2..0....0..0....0..0....2..1....1..0....0..1....2..1....2..1
..0..0....0..0....0..0....2..0....2..2....2..1....0..0....1..2....1..1....2..1

Crossrefs

Sequence in context: A369114 A020108 A323696 * A361881 A303558 A193661

Adjacent sequences: A231654 A231655 A231656 * A231658 A231659 A231660

Keyword

nonn

Author

R. H. Hardin, Nov 12 2013

Status

approved