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A305226 Number of nX4 0..1 arrays with every element unequal to 0, 1, 2, 3 or 8 king-move adjacent elements, with upper left element zero. 1
8, 49, 54, 116, 253, 541, 1248, 2831, 6471, 14788, 33887, 77571, 177642, 406875, 931841, 2134242, 4888087, 11195485, 25641380, 58727691, 134506571, 308066476, 705578355, 1616017727, 3701237834, 8477110559, 19415506245, 44468203154 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 4 of A305230.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +3*a(n-2) +a(n-3) -a(n-4) -3*a(n-5) -2*a(n-6) +2*a(n-7) for n>9
EXAMPLE
Some solutions for n=5
..0..1..0..0. .0..0..0..0. .0..0..1..0. .0..0..0..0. .0..0..0..0
..1..1..1..0. .1..1..1..1. .0..1..1..1. .0..0..0..0. .0..0..0..0
..1..1..1..1. .1..1..1..1. .1..1..1..0. .0..0..0..0. .0..0..0..0
..1..1..0..1. .1..1..0..1. .1..1..0..0. .0..0..0..0. .0..0..0..0
..0..1..1..1. .0..1..1..1. .1..0..0..0. .1..0..0..1. .1..1..1..1
CROSSREFS
Cf. A305230.
Sequence in context: A080493 A355434 A303723 * A304771 A316514 A352179
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 27 2018
STATUS
approved

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Last modified June 25 04:54 EDT 2024. Contains 373697 sequences. (Running on oeis4.)