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A302679
Number of nX7 0..1 arrays with every element equal to 0, 1, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
21, 23, 94, 217, 661, 2013, 6311, 19497, 60253, 186797, 578385, 1790605, 5545571, 17172267, 53173813, 164661159, 509890659, 1578918645, 4889288817, 15140189411, 46883090855, 145178205375, 449559001303, 1392104734057, 4310792424591
OFFSET
1,1
COMMENTS
Column 7 of A302680.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +a(n-2) +12*a(n-3) +14*a(n-4) +10*a(n-5) -9*a(n-6) -26*a(n-7) +2*a(n-8) +18*a(n-9) +6*a(n-10) -4*a(n-12) for n>19
EXAMPLE
Some solutions for n=5
..0..1..0..1..0..1..0. .0..0..0..1..0..1..0. .0..1..0..1..1..1..0
..0..0..0..1..0..0..0. .0..1..0..1..1..1..0. .0..1..0..1..0..1..0
..0..1..0..1..0..1..0. .0..1..0..1..0..1..0. .0..0..0..1..0..1..0
..0..1..0..1..0..1..0. .0..1..0..1..0..0..0. .0..1..0..1..0..1..0
..0..1..0..0..0..1..0. .0..1..1..1..0..1..0. .0..1..0..1..1..1..0
CROSSREFS
Cf. A302680.
Sequence in context: A270108 A335189 A304269 * A302514 A303313 A257642
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 11 2018
STATUS
approved