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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

(list; graph; refs; listen; history; text; internal format)

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