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 A221287 Equals two maps: number of n X n binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..3 n X n array 0
 1, 4, 92, 9107, 4983598, 10344276279 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Diagonal of A221290 LINKS EXAMPLE Some solutions for n=3 ..0..0..0....0..0..1....0..1..0....0..0..0....0..0..1....0..1..1....0..0..1 ..1..1..0....1..0..1....0..1..0....1..0..1....0..1..0....0..1..1....1..0..1 ..1..1..0....1..1..0....1..1..0....1..0..0....1..1..0....0..1..0....1..0..0 CROSSREFS Sequence in context: A012071 A012217 A012135 * A177411 A219891 A050878 Adjacent sequences:  A221284 A221285 A221286 * A221288 A221289 A221290 KEYWORD nonn AUTHOR R. H. Hardin Jan 09 2013 STATUS approved

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Last modified May 18 06:33 EDT 2021. Contains 343994 sequences. (Running on oeis4.)