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 A279574 Number of n X 2 0..2 arrays with no element equal to a strict majority of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards. 1
 0, 4, 40, 352, 3008, 25280, 209792, 1723392, 14039040, 113562624, 913131520, 7304519680, 58170228736, 461421658112, 3647369216000, 28741570396160, 225854805245952, 1770332698705920, 13844879799484416, 108048964894326784 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 16*a(n-1) - 72*a(n-2) + 64*a(n-3) - 16*a(n-4). Empirical g.f.: 4*x^2*(1 - 6*x) / (1 - 8*x + 4*x^2)^2. - Colin Barker, Feb 11 2019 EXAMPLE Some solutions for n=4: ..0..1. .0..1. .0..1. .0..1. .0..0. .0..0. .0..0. .0..1. .0..1. .0..1 ..2..0. .2..0. .2..1. .2..0. .1..0. .1..0. .1..0. .0..2. .2..1. .0..2 ..0..2. .2..2. .1..0. .2..2. .0..2. .1..0. .1..0. .2..2. .2..2. .0..1 ..1..1. .1..1. .2..2. .2..0. .1..2. .1..2. .2..0. .1..2. .1..1. .2..2 CROSSREFS Column 2 of A279580. Sequence in context: A145730 A069721 A223176 * A327675 A191681 A222273 Adjacent sequences:  A279571 A279572 A279573 * A279575 A279576 A279577 KEYWORD nonn AUTHOR R. H. Hardin, Dec 15 2016 STATUS approved

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Last modified January 19 14:34 EST 2022. Contains 350466 sequences. (Running on oeis4.)