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 A218280 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..4 n X n array 0
 1, 15, 511, 65507, 33549827, 68710447465, 562876144341077 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Diagonal of A218288 LINKS EXAMPLE Some solutions for n=3 ..1..1..0....1..0..1....1..0..1....1..0..0....0..1..0....0..1..0....1..1..0 ..0..0..1....1..0..0....1..0..1....1..0..1....0..0..1....0..0..1....0..0..0 ..1..0..1....0..1..1....1..1..0....1..0..1....0..1..1....0..0..1....1..0..0 CROSSREFS Sequence in context: A203326 A092561 A218312 * A218632 A218235 A212739 Adjacent sequences:  A218277 A218278 A218279 * A218281 A218282 A218283 KEYWORD nonn AUTHOR R. H. Hardin Oct 25 2012 STATUS approved

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Last modified January 18 15:16 EST 2021. Contains 340254 sequences. (Running on oeis4.)