A221389 Number of 3 X n arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no 2-loops and with no occupancy greater than 2.

0, 0, 4, 94, 1450, 20689, 284702, 3856027, 51806212, 693213401, 9256626752, 123474805622, 1646142914632, 21939928353674, 292375085482054, 3895949812693799, 51912242778609770, 691699897071467742

Offset

1,3

Comments

Row 3 of A221388.

Links

R. H. Hardin, Table of n, a(n) for n = 1..37

Example

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

Crossrefs

Cf. A221388.

Sequence in context: A321221 A116291 A061992 * A220374 A220429 A210857

Adjacent sequences: A221386 A221387 A221388 * A221390 A221391 A221392

Keyword

nonn

Author

R. H. Hardin, Jan 14 2013

Status

approved