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A218188
Hilltop maps: number of n X n binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or vertical neighbor in a random 0..3 n X n array
0
1, 15, 507, 65251, 33407143, 68410191725, 560375293762217
OFFSET
1,2
COMMENTS
Diagonal of A218196
EXAMPLE
Some solutions for n=3
..1..1..1....0..0..1....0..0..0....1..1..0....0..0..0....1..0..0....0..0..1
..0..0..0....1..1..0....0..0..0....1..1..1....0..0..0....1..0..0....1..0..1
..1..0..1....0..0..1....1..1..0....1..0..0....0..1..0....1..1..0....1..1..1
CROSSREFS
Sequence in context: A203525 A249962 A004703 * A218365 A203326 A092561
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 23 2012
STATUS
approved