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A218639 Hilltop maps: number of 4Xn binary arrays indicating the locations of corresponding elements not exceeded by any horizontal, diagonal or antidiagonal neighbor in a random 0..3 4Xn array 1
1, 251, 4087, 65523, 1048363, 16773477, 268375113, 4294000777, 68704008397, 1099264075379, 17588224239783, 281411572315259, 4502584908606667, 72041354562688477, 1152661609402891673, 18442584732844711745 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Row 4 of A218638
LINKS
FORMULA
Empirical: a(n) = 15*a(n-1) +14*a(n-2) +30*a(n-3) +27*a(n-4) +73*a(n-5) +96*a(n-6) +230*a(n-7) +167*a(n-8) -69*a(n-9) -116*a(n-10) -60*a(n-11) -13*a(n-12) -95*a(n-13) -254*a(n-14) -292*a(n-15) -120*a(n-16) for n>17
EXAMPLE
Some solutions for n=3
..1..0..0....1..1..1....0..0..1....1..1..0....0..1..0....1..0..0....1..1..0
..1..1..0....0..1..1....0..1..1....1..1..1....0..1..1....1..0..0....0..1..0
..0..1..1....1..0..1....0..0..0....0..0..1....0..1..1....1..0..0....1..0..0
..0..0..1....0..0..1....1..1..1....0..1..1....1..0..0....0..1..1....0..0..1
CROSSREFS
Sequence in context: A183840 A340636 A234929 * A090834 A078968 A365468
KEYWORD
nonn
AUTHOR
R. H. Hardin Nov 03 2012
STATUS
approved

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Last modified May 23 20:34 EDT 2024. Contains 372765 sequences. (Running on oeis4.)