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A297729
Number of nX4 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 or 4 neighboring 1s.
1
1, 15, 34, 93, 502, 1443, 4676, 19601, 62749, 212944, 806349, 2715704, 9383104, 34004795, 117138709, 407907961, 1450394287, 5045390250, 17630646061, 62173678114, 217189833443, 760130838978, 2670989983319, 9347287498273
OFFSET
1,2
COMMENTS
Column 4 of A297733.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +a(n-2) +31*a(n-3) -6*a(n-4) +18*a(n-5) -153*a(n-6) +7*a(n-7) -67*a(n-8) +243*a(n-9) -4*a(n-10) -3*a(n-11) -89*a(n-12) +29*a(n-13) +67*a(n-14) -25*a(n-15) -44*a(n-16) -4*a(n-17) +12*a(n-18) +3*a(n-19)
EXAMPLE
Some solutions for n=7
..0..0..0..0. .0..1..1..0. .0..1..1..0. .0..0..0..0. .0..1..1..0
..0..0..0..0. .0..1..1..0. .1..1..0..0. .1..1..0..0. .1..0..0..1
..0..0..0..0. .0..0..0..0. .0..0..0..0. .0..1..1..0. .0..1..1..0
..0..0..1..0. .0..1..0..0. .0..1..0..0. .0..0..0..0. .0..0..0..0
..0..1..0..1. .1..1..1..0. .1..1..1..0. .1..1..1..1. .0..1..1..0
..0..1..1..0. .0..0..0..0. .1..0..1..0. .1..1..1..1. .1..0..0..1
..0..0..1..1. .0..0..0..0. .0..1..0..0. .0..0..0..0. .0..1..1..0
CROSSREFS
Cf. A297733.
Sequence in context: A168573 A139578 A345733 * A156662 A027443 A205148
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 04 2018
STATUS
approved