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A219079 Hilltop maps: number of 2Xn binary arrays indicating the locations of corresponding elements not exceeded by any horizontal, diagonal or antidiagonal neighbor in a random 0..1 2Xn array 2
1, 11, 47, 165, 625, 2435, 9367, 35901, 137865, 529675, 2034399, 7813333, 30009313, 115260115, 442689383, 1700273453, 6530386425, 25081819099, 96333894191, 369997847365, 1421082488529, 5458073486883, 20963291245879, 80515511728413 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row 2 of A219078

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 3*a(n-1) +a(n-2) +7*a(n-3) +6*a(n-4)

EXAMPLE

Some solutions for n=3

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

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

CROSSREFS

Sequence in context: A178572 A036489 A076306 * A059323 A267614 A123984

Adjacent sequences:  A219076 A219077 A219078 * A219080 A219081 A219082

KEYWORD

nonn

AUTHOR

R. H. Hardin Nov 11 2012

STATUS

approved

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Last modified June 20 00:47 EDT 2019. Contains 324223 sequences. (Running on oeis4.)