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A198907
Number of n X n 0..7 arrays with values 0..7 introduced in row major order and no element equal to any horizontal or vertical neighbor
2
1, 4, 2051, 319608038, 4717456775959530, 2869765342757082981876352
OFFSET
1,2
COMMENTS
Diagonal of A198914
LINKS
Jean-François Alcover, Table of n, a(n) for n = 1..12
EXAMPLE
Some solutions with values 0 to 7 for n=3
..0..1..2....0..1..2....0..1..2....0..1..2....0..1..2....0..1..2....0..1..2
..3..4..5....3..4..5....3..4..5....3..4..1....3..4..5....3..4..5....3..4..5
..6..7..4....1..6..7....4..6..7....5..6..7....2..6..7....6..0..7....6..2..7
MATHEMATICA
A198914 = Cases[Import["https://oeis.org/A198914/b198914.txt", "Table"], {_, _}][[All, 2]];
a[n_] := A198914[[2 n^2 - 2 n + 1]];
Table[a[n], {n, 1, 12}] (* Jean-François Alcover, Sep 23 2019 *)
CROSSREFS
Sequence in context: A198716 A365369 A004815 * A207863 A220941 A012869
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 31 2011
STATUS
approved