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A221305
Number of nX3 arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, with every occupancy equal to zero or two
1
0, 10, 0, 312, 0, 10042, 0, 319226, 0, 10133708, 0, 321533586, 0, 10200714244, 0, 323608871782, 0, 10266122386790, 0, 325680263163306, 0, 10331804351728716, 0, 327763686122256921, 0, 10397896202291347434, 0, 329860349856599608391, 0
OFFSET
1,2
COMMENTS
Column 3 of A221308
LINKS
FORMULA
Empirical: a(n) = 33*a(n-2) -2*a(n-4) -1074*a(n-6) -4389*a(n-8) -8373*a(n-10) -9016*a(n-12) -5198*a(n-14) -28*a(n-16) +3296*a(n-18) +3856*a(n-20) +2610*a(n-22) +1148*a(n-24) +302*a(n-26) +8*a(n-28) -28*a(n-30) -8*a(n-32) for n>34
EXAMPLE
Some solutions for n=4
..0..2..2....0..0..2....0..2..2....2..2..0....0..2..0....0..2..0....0..2..2
..0..0..0....2..2..0....0..2..0....0..2..0....0..2..0....2..2..0....0..2..2
..2..2..0....2..0..2....0..2..2....2..2..2....0..2..0....0..2..0....0..2..0
..0..2..2....0..2..0....2..0..0....0..0..0....2..2..2....2..2..0....0..2..0
CROSSREFS
Sequence in context: A326719 A070190 A216797 * A173775 A222401 A287465
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 09 2013
STATUS
approved