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A221826
Number of nX4 arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without 2-loops or left turns
1
0, 73, 2879, 115417, 4755445, 194407111, 7954432829, 325446165881, 13315083231576, 544765825231628, 22288229643043523, 911887582567144091, 37308434607556030347, 1526415443763878545790, 62450867501566841285468
OFFSET
1,2
COMMENTS
Column 4 of A221828
LINKS
EXAMPLE
Some solutions for n=3
..0..2..2..1....1..1..1..1....0..2..2..2....0..2..0..2....0..1..0..1
..1..0..1..0....2..1..1..0....0..1..1..1....2..1..0..1....0..3..1..2
..2..1..1..1....0..2..2..0....1..0..1..1....1..1..2..0....1..1..2..0
CROSSREFS
Sequence in context: A361491 A017789 A017736 * A093273 A183540 A022242
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 26 2013
STATUS
approved