A221390 Number of 4Xn 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, 13, 1198, 52320, 2204556, 86673898, 3361458245, 128992693561, 4928816080380, 187851827622672, 7150418585672281, 271982464009887803, 10341601574159713990, 393139667142067892978, 14943725056237306101598

Offset

1,3

Comments

Row 4 of A221388

Links

R. H. Hardin, Table of n, a(n) for n = 1..21

Example

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

Crossrefs

Sequence in context: A195520 A128897 A201265 * A226095 A220619 A178560

Adjacent sequences: A221387 A221388 A221389 * A221391 A221392 A221393

Keyword

nonn

Author

R. H. Hardin Jan 14 2013

Status

approved