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A221274 Number of nX4 arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, with every occupancy equal to zero or two 1
1, 25, 100, 1089, 6724, 56644, 400689, 3122289, 23049601, 175350564, 1311815961, 9905822784, 74413292944, 560619075025, 4216817073121, 31746204178129, 238880949939076, 1798010762343849, 13531178521076836, 101839561889056996 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 4 of A221275

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..21

FORMULA

Empirical: a(n) = 7*a(n-1) +16*a(n-2) -105*a(n-3) +108*a(n-4) +10*a(n-5) -56*a(n-6) -53*a(n-7) +23*a(n-8) -6*a(n-9) +a(n-10)

EXAMPLE

Some solutions for n=4

..0..2..2..0....0..2..2..0....0..0..2..2....0..0..2..0....2..2..2..0

..2..0..0..0....2..0..0..2....2..2..0..0....0..2..2..2....0..2..0..2

..0..2..2..0....2..2..0..2....0..0..2..2....2..0..2..2....0..0..2..0

..0..2..2..2....0..0..2..0....0..2..2..0....0..2..0..0....2..2..0..0

CROSSREFS

Sequence in context: A134422 A016850 A309779 * A042220 A114254 A042222

Adjacent sequences:  A221271 A221272 A221273 * A221275 A221276 A221277

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 09 2013

STATUS

approved

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Last modified August 11 00:32 EDT 2020. Contains 336403 sequences. (Running on oeis4.)