A221305 - OEIS

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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

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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Column 3 of A221308

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

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

Adjacent sequences: A221302 A221303 A221304 * A221306 A221307 A221308

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 09 2013

STATUS

approved