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 A221414 Number of nX3 arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, with every occupancy equal to zero or two 1
 0, 10, 0, 150, 0, 2250, 0, 33750, 0, 506250, 0, 7593750, 0, 113906250, 0, 1708593750, 0, 25628906250, 0, 384433593750, 0, 5766503906250, 0, 86497558593750, 0, 1297463378906250, 0, 19461950683593750, 0, 291929260253906250, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Column 3 of A221419 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 15*a(n-2) EXAMPLE Some solutions for n=4 ..0..2..0....2..2..0....0..2..2....2..0..0....2..2..0....2..0..0....0..2..2 ..2..2..0....0..2..0....0..2..0....0..2..2....0..0..2....0..2..0....0..2..0 ..2..2..0....2..0..2....0..2..0....2..0..0....2..0..0....2..2..0....2..0..0 ..0..0..2....0..2..0....2..2..0....0..2..2....2..2..0....2..2..0....2..2..0 CROSSREFS Sequence in context: A285536 A285477 A089831 * A326719 A070190 A216797 Adjacent sequences: A221411 A221412 A221413 * A221415 A221416 A221417 KEYWORD nonn AUTHOR R. H. Hardin Jan 15 2013 STATUS approved

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Last modified September 22 03:20 EDT 2023. Contains 365503 sequences. (Running on oeis4.)