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A193270
Number of n X n symmetric 0..4 arrays with no element equal to any horizontal or vertical neighbor and with new values 0..4 introduced in lower triangular row major order
1
1, 2, 41, 5913, 3218949, 5746014471, 33346758707039, 629041120985307133, 38569311842617827824519, 7686740212720656511786911885, 4979434019923682892902923543291527
OFFSET
1,2
LINKS
EXAMPLE
Some solutions for 4X4
..0..1..0..2....0..1..0..1....0..1..0..2....0..1..3..1....0..1..3..4
..1..2..3..1....1..2..1..0....1..2..1..3....1..2..4..3....1..2..1..0
..0..3..1..0....0..1..2..1....0..1..2..4....3..4..1..4....3..1..4..3
..2..1..0..1....1..0..1..3....2..3..4..3....1..3..4..1....4..0..3..1
CROSSREFS
Sequence in context: A098634 A278847 A297007 * A350859 A076391 A348773
KEYWORD
nonn
AUTHOR
R. H. Hardin Jul 20 2011
STATUS
approved