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A303723
Number of n X 4 0..1 arrays with every element unequal to 0, 1, 2 or 3 king-move adjacent elements, with upper left element zero.
1
8, 49, 46, 84, 133, 221, 406, 743, 1327, 2396, 4385, 8003, 14556, 26527, 48421, 88330, 161061, 293777, 535950, 977643, 1783259, 3252908, 5933861, 10824167, 19744652, 36017043, 65700297, 119846482, 218616585, 398787421, 727444438, 1326960543
OFFSET
1,1
COMMENTS
Column 4 of A303727.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +a(n-2) +a(n-3) +a(n-4) -a(n-5) -2*a(n-6) for n>8.
EXAMPLE
Some solutions for n=5
..0..1..1..1. .0..0..0..0. .0..1..1..1. .0..1..1..1. .0..1..1..1
..0..1..1..1. .0..0..0..0. .1..1..1..0. .1..1..1..1. .1..1..1..1
..0..1..1..1. .0..0..0..0. .1..1..0..0. .1..1..1..0. .1..1..1..1
..0..1..1..1. .0..0..0..1. .1..0..0..0. .1..1..0..0. .1..1..1..0
..0..1..1..0. .1..0..1..1. .0..0..0..0. .1..0..0..0. .0..1..0..0
CROSSREFS
Cf. A303727.
Sequence in context: A010568 A080493 A355434 * A305226 A304771 A316514
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 29 2018
STATUS
approved