A221379 Number of nX5 arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with every occupancy equal to zero or two

0, 8, 0, 189, 0, 5040, 0, 134521, 0, 3580920, 0, 95235525, 0, 2532193248, 0, 67323825121, 0, 1789924262120, 0, 47588184605133, 0, 1265212011626640, 0, 33637786102201993, 0, 894317001840696408, 0, 23776918341948436245, 0

Offset

1,2

Comments

Column 5 of A221381

Links

R. H. Hardin, Table of n, a(n) for n = 1..48

Formula

Empirical: a(n) = 42*a(n-2) -497*a(n-4) +2546*a(n-6) -6335*a(n-8) +7910*a(n-10) -5003*a(n-12) +1526*a(n-14) -196*a(n-16) +8*a(n-18)

Example

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

Crossrefs

Sequence in context: A221887 A277257 A121770 * A013376 A221421 A371990

Adjacent sequences: A221376 A221377 A221378 * A221380 A221381 A221382

Keyword

nonn

Author

R. H. Hardin Jan 14 2013

Status

approved