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A194538
Number of lower triangles of an n X n 0..6 array with new values introduced in row major order 0..6 and no element equal to more than one horizontal or vertical neighbor
0
1, 4, 132, 67377, 543350470, 40994098419294, 21253155706215768591, 71381360690596538575641162
OFFSET
1,2
COMMENTS
Column 6 of A194540
EXAMPLE
Some solutions for 3X3
..0......0......0......0......0......0......0......0......0......0......0
..0.1....1.2....1.2....1.1....1.2....1.2....1.1....1.0....0.1....1.2....1.1
..2.2.0..1.0.2..0.3.3..2.0.0..2.3.4..2.0.0..2.2.3..2.1.3..2.3.0..2.3.1..2.0.1
CROSSREFS
Sequence in context: A338040 A204077 A194537 * A194539 A146547 A274703
KEYWORD
nonn
AUTHOR
R. H. Hardin Aug 28 2011
STATUS
approved