A221892 Number of 3Xn arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, without 2-loops or left turns

0, 0, 0, 202, 2722, 31881, 416630, 5496803, 71900708, 940934266, 12320347932, 161293030438, 2111496138082, 27642157184325, 361871500036368, 4737358281430753, 62018044719943396, 811895156827216792

Offset

1,4

Comments

Row 3 of A221890

Links

R. H. Hardin, Table of n, a(n) for n = 1..70

Example

Some solutions for n=4
..0..1..1..0....0..1..1..1....0..2..1..1....0..3..2..1....0..3..2..0
..0..2..3..1....0..1..3..0....0..2..2..0....1..1..2..0....1..1..1..1
..1..2..1..0....1..3..1..0....1..1..2..0....0..1..1..0....0..1..2..0

Crossrefs

Sequence in context: A252993 A252987 A229640 * A332120 A064100 A159382

Adjacent sequences: A221889 A221890 A221891 * A221893 A221894 A221895

Keyword

nonn

Author

R. H. Hardin Jan 30 2013

Status

approved