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A303794 Number of nX2 0..1 arrays with every element unequal to 0, 1, 2 or 4 king-move adjacent elements, with upper left element zero. 8
2, 4, 12, 24, 64, 184, 432, 1088, 2944, 7360, 18496, 48384, 123392, 312320, 804864, 2061824, 5248000, 13449216, 34455552, 87961600, 225038336, 576143360, 1472741376, 3766452224, 9638051840, 24648581120, 63037702144, 161266270208 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 2 of A303800.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +8*a(n-3) -8*a(n-4) -8*a(n-5) for n>6
EXAMPLE
Some solutions for n=5
..0..1. .0..1. .0..1. .0..0. .0..0. .0..0. .0..1. .0..0. .0..1. .0..0
..1..0. .1..0. .0..1. .0..0. .1..0. .0..1. .1..0. .1..1. .1..0. .1..1
..1..1. .1..1. .0..0. .0..1. .1..0. .0..1. .0..0. .1..1. .0..0. .1..1
..1..1. .0..1. .0..0. .0..1. .1..1. .0..0. .1..0. .0..1. .1..0. .1..0
..0..0. .1..0. .0..0. .1..1. .1..1. .0..0. .1..0. .0..1. .0..1. .1..0
CROSSREFS
Cf. A303800.
Sequence in context: A036045 A331392 A100538 * A135139 A161894 A062177
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 30 2018
STATUS
approved

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Last modified March 19 02:49 EDT 2024. Contains 370952 sequences. (Running on oeis4.)