A221805 Number of nX2 arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without move-in move-out straight through or left turns

1, 10, 41, 233, 1156, 6048, 30973, 159968, 823413, 4244066, 21863362, 112652884, 580406183, 2990444375, 15407563307, 79384245250, 409009933399, 2107335620744, 10857590040499, 55941385316549, 288225882117252, 1485021507246365

Offset

1,2

Comments

Column 2 of A221809

Links

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

Formula

Empirical: a(n) = a(n-1) +18*a(n-2) +22*a(n-3) -14*a(n-4) -39*a(n-5) -44*a(n-6) -6*a(n-7) +7*a(n-8) +3*a(n-9) +4*a(n-10) +a(n-11)

Example

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

Crossrefs

Sequence in context: A061003 A211064 A048879 * A089211 A220927 A222858

Adjacent sequences: A221802 A221803 A221804 * A221806 A221807 A221808

Keyword

nonn

Author

R. H. Hardin Jan 26 2013

Status

approved