

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
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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(n1) +16*a(n2) 105*a(n3) +108*a(n4) +10*a(n5) 56*a(n6) 53*a(n7) +23*a(n8) 6*a(n9) +a(n10)


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



