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A221656
Number of 2Xn arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, without move-in move-out left turns
1
0, 4, 24, 165, 1054, 6862, 44576, 289789, 1883406, 12241008, 79558150, 517073937, 3360625086, 21841749571, 141956320765, 922618247832, 5996382690315, 38972354390400, 253293441134093, 1646232780191728, 10699378374870619
OFFSET
1,2
COMMENTS
Row 2 of A221655
LINKS
FORMULA
Empirical: a(n) = 9*a(n-1) -15*a(n-2) -15*a(n-3) +52*a(n-4) -51*a(n-5) -a(n-6) +127*a(n-7) -32*a(n-8) -28*a(n-9) +25*a(n-10) for n>12
EXAMPLE
Some solutions for n=3
..1..2..0....1..3..1....1..3..0....1..2..0....1..4..1....0..0..0....0..4..1
..1..2..0....0..1..0....0..1..1....0..2..1....0..0..0....1..4..1....1..0..0
CROSSREFS
Sequence in context: A027079 A213441 A238299 * A366623 A339346 A214377
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 21 2013
STATUS
approved