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A193268
Number of n X n symmetric 0..2 arrays with no element equal to any horizontal or vertical neighbor and with new values 0..2 introduced in lower triangular row major order
1
1, 2, 12, 108, 1476, 30744, 978696, 47696148, 3562705944, 408229283700, 71800542715032, 19393574332167000, 8047409187443508720, 5131576344077602362144, 5029742282540253810124752
OFFSET
1,2
LINKS
EXAMPLE
Some solutions for 4X4
..0..1..0..1....0..1..2..0....0..1..0..2....0..1..0..1....0..1..2..0
..1..2..1..2....1..2..1..2....1..0..2..1....1..0..2..0....1..2..0..2
..0..1..2..0....2..1..2..1....0..2..0..2....0..2..0..1....2..0..2..1
..1..2..0..2....0..2..1..0....2..1..2..0....1..0..1..2....0..2..1..0
CROSSREFS
Sequence in context: A194786 A339301 A179493 * A235601 A007724 A217800
KEYWORD
nonn
AUTHOR
R. H. Hardin Jul 20 2011
STATUS
approved