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A221831
Number of 4Xn arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without 2-loops or left turns
1
0, 64, 2930, 115417, 4715043, 192788993, 7888216533, 322723834959, 13203608881221, 540203150208573, 22101534579211095, 904249026745794715, 36995912673327194833, 1513629078095632460534, 61927733346071816062294
OFFSET
1,2
COMMENTS
Row 4 of A221828
LINKS
EXAMPLE
Some solutions for n=3
..1..1..1....1..1..0....1..1..1....0..2..0....0..3..1....0..2..0....1..1..1
..2..0..1....2..1..1....2..2..0....1..2..0....0..1..1....2..2..0....1..2..0
..1..1..0....1..0..2....2..0..0....0..2..1....1..1..1....2..1..0....1..1..1
..2..1..1....1..1..1....1..1..1....1..3..0....1..2..0....1..1..1....1..2..0
CROSSREFS
Sequence in context: A295714 A187623 A187631 * A282397 A297100 A221090
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 26 2013
STATUS
approved