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A202975 Number of nX4 0..1 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors 1
1, 7, 58, 385, 2582, 17740, 122468, 846908, 5858575, 40519184, 280214415, 1937863565, 13401760093, 92683431379, 640976755990, 4432841883249, 30656469034888, 212012773252576, 1466229429328620, 10140090725898534 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Column 4 of A202979
LINKS
FORMULA
Empirical: a(n) = 10*a(n-1) -31*a(n-2) +82*a(n-3) -131*a(n-4) +226*a(n-5) -319*a(n-6) +206*a(n-7) -574*a(n-8) +483*a(n-9) -432*a(n-10) +517*a(n-11) +132*a(n-12) +746*a(n-13) -145*a(n-14) -228*a(n-15) -6*a(n-16) +41*a(n-17) +3*a(n-18) -3*a(n-19)
EXAMPLE
Some solutions for n=5
..1..1..0..0....1..1..1..0....1..1..0..0....1..1..1..1....0..1..1..0
..1..1..1..1....1..0..1..1....1..1..1..1....1..0..1..1....1..1..1..1
..0..0..1..1....1..0..0..1....1..1..1..1....1..0..1..0....1..0..1..1
..0..1..1..1....1..0..1..1....1..1..1..1....1..1..1..1....1..1..0..1
..0..1..1..0....1..1..1..0....0..1..1..0....0..1..1..1....0..1..1..1
CROSSREFS
Sequence in context: A225160 A219974 A266051 * A051816 A015566 A238810
KEYWORD
nonn
AUTHOR
R. H. Hardin Dec 26 2011
STATUS
approved

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Last modified July 17 19:13 EDT 2024. Contains 374377 sequences. (Running on oeis4.)