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 A208045 Number of n X n 0..3 arrays with new values 0..3 introduced in row major order and no element equal to any horizontal, vertical or antidiagonal neighbor (colorings ignoring permutations of colors) 1
 1, 2, 44, 1904, 168096, 30818432, 11838995200, 9578237457408, 16372889877477376, 59262411624914853888, 454901302416508366209024, 7413673375795915677473636352 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Diagonal of A208050 LINKS EXAMPLE Some solutions for n=4 ..0..1..2..1....0..1..2..1....0..1..2..3....0..1..0..1....0..1..2..1 ..2..0..3..2....2..3..0..3....3..0..1..0....2..3..2..3....2..3..0..2 ..3..2..1..0....0..1..2..0....1..2..3..1....0..1..0..1....0..2..1..3 ..0..3..2..1....2..3..1..3....3..1..0..2....2..3..2..0....1..0..2..1 MATHEMATICA A208050 = Cases[Import["https://oeis.org/A208050/b208050.txt", "Table"], {_, _}][[All, 2]]; a[n_] := A208050[[2 n^2 - 2 n + 1]]; Table[a[n], {n, 1, 12}] (* Jean-François Alcover, Sep 23 2019 *) CROSSREFS Sequence in context: A213067 A140795 A161744 * A267070 A054732 A161722 Adjacent sequences:  A208042 A208043 A208044 * A208046 A208047 A208048 KEYWORD nonn AUTHOR R. H. Hardin Feb 22 2012 STATUS approved

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Last modified August 3 13:49 EDT 2020. Contains 336198 sequences. (Running on oeis4.)