A221895 Number of nX3 arrays of occupancy after each element stays put or moves to some horizontal, vertical or antidiagonal neighbor, without move-in move-out straight through or left turns.

6, 258, 7667, 235332, 7197649, 220361275, 6744533268, 206439650412, 6318757208626, 193406107213008, 5919823712888467, 181195475755599060, 5546077402982111186, 169755753751290765761, 5195927470447150844696

Offset: 1

Author

R. H. Hardin Jan 30 2013

Keywords

• nonn

Comments

Column 3 of A221898

Examples

			Some solutions for n=3
..0..0..0....0..1..2....1..0..2....0..1..1....3..0..2....1..0..1....0..2..0
..3..1..2....0..3..0....1..1..0....0..4..2....0..3..0....3..1..0....4..0..0
..1..0..2....1..2..0....2..1..1....1..0..0....0..0..1....0..0..3....0..3..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..163

Formula

Empirical: a(n) = 14*a(n-1) +401*a(n-2) +3090*a(n-3) +7741*a(n-4) -40484*a(n-5) -361940*a(n-6) -1090743*a(n-7) -1171988*a(n-8) +2002414*a(n-9) +720120*a(n-10) -7394610*a(n-11) [phone]*a(n-12) -2069693*a(n-13) -44623518*a(n-14) [phone]*a(n-15) -104778098*a(n-16) [phone]*a(n-17) [phone]*a(n-18) -174397406*a(n-19) [phone]*a(n-20) [phone]*a(n-21) -214551956*a(n-22) [phone]*a(n-23) [phone]*a(n-24) -10733620*a(n-25) +1466700*a(n-26) -21780*a(n-27) -2160*a(n-28)