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A195952 Number of lower triangles of an n X n 0..4 array with each element equal to the number of its horizontal and vertical neighbors unequal to itself 0
1, 2, 2, 3, 3, 8, 3, 33, 62, 161, 137, 1336, 2528, 8851, 25727, 92540, 377525, 1909048 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
EXAMPLE
Some solutions for n=8
..1................1................1................1
..3.2..............2.1..............2.1..............3.1
..1.1.1............2.1.1............2.1.1............1.1.2
..1.1.4.1..........1.1.3.1..........1.1.3.1..........1.1.4.1
..3.1.1.1.2........1.1.3.1.1........1.1.3.1.1........2.1.1.1.1
..1.1.1.1.4.1......2.1.1.1.3.1......2.1.1.1.4.2......2.1.1.3.3.1
..1.3.3.1.1.1.1....2.1.1.1.3.1.1....2.1.1.1.1.1.1....1.1.1.1.1.1.1
..1.2.2.1.1.2.2.1..1.1.3.1.1.1.3.1..1.1.2.2.1.1.3.1..1.2.2.1.1.2.2.1
CROSSREFS
Sequence in context: A252582 A181577 A110880 * A236545 A321327 A370898
KEYWORD
nonn
AUTHOR
R. H. Hardin Sep 25 2011
STATUS
approved

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Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)