A221726 - OEIS

A221726

Number of nX3 arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, with every occupancy equal to zero or two

0, 16, 0, 464, 0, 13948, 0, 420736, 0, 12695288, 0, 383074904, 0, 11559126552, 0, 348791805904, 0, 10524646286488, 0, 317576778411352, 0, 9582745781519416, 0, 289155325092787296, 0, 8725140362031620984, 0, 263277441988312544616, 0

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OFFSET

1,2

COMMENTS

Column 3 of A221728

LINKS

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

FORMULA

Empirical: a(n) = 44*a(n-2) -462*a(n-4) +1400*a(n-6) -1417*a(n-8) -448*a(n-10) -280*a(n-12) +100*a(n-14)

EXAMPLE

Some solutions for n=4

..0..0..2....0..2..2....0..2..0....2..2..0....2..2..0....2..0..0....0..2..2