A221375 Number of nX3 arrays of occupancy after each element stays put or moves to some horizontal, vertical or antidiagonal neighbor, with no occupancy greater than 2

7, 139, 3017, 68006, 1548941, 35365731, 807887304, 18456843366, 421665253450, 9633337841423, 220081885496712, 5027948655020101, 114867396786410407, 2624232861115617998, 59952562195425809756, 1369660717750392920845

Offset

1,1

Comments

Column 3 of A221378

Links

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

Formula

Empirical: a(n) = 53*a(n-1) -1022*a(n-2) +9430*a(n-3) -46832*a(n-4) +127474*a(n-5) -173901*a(n-6) +70397*a(n-7) +60137*a(n-8) -23731*a(n-9) -21147*a(n-10) -4513*a(n-11) -40*a(n-12) +152*a(n-13) +12*a(n-14) for n>15

Example

Some solutions for n=3
..0..2..1....0..1..2....1..0..1....1..2..0....2..0..1....0..2..1....1..0..1
..2..0..0....1..0..2....2..0..2....1..2..1....0..1..2....0..1..1....1..0..2
..0..2..2....1..1..1....0..2..1....1..0..1....2..0..1....2..0..2....0..2..2

Crossrefs

Sequence in context: A056254 A137463 A274525 * A351334 A190195 A126156

Adjacent sequences: A221372 A221373 A221374 * A221376 A221377 A221378

Keyword

nonn

Author

R. H. Hardin Jan 13 2013

Status

approved