A218803 - OEIS

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A218803

Hilltop maps: number of n X n binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or antidiagonal neighbor in a random 0..3 n X n array

1, 15, 481, 63499, 32496361, 66531801953, 544920898689805, 17853080088569676529, 2339690141788794554403313, 1226489723856405899902679483839

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Diagonal of A218810

LINKS

Table of n, a(n) for n=1..10.

EXAMPLE

Some solutions for n=3

..0..0..1....0..1..0....1..1..0....0..1..0....0..0..0....1..1..0....1..1..1

..1..0..1....0..0..0....1..0..0....0..1..0....0..1..0....0..1..1....1..1..0