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A318041 Number of nX4 0..1 arrays with every element unequal to 0, 2, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 1
1, 3, 21, 140, 905, 6179, 42793, 297043, 2056698, 14234986, 98543469, 682235511, 4723208829, 32699080489, 226377712742, 1567228238886, 10850029939485, 75115505261838, 520029800880263, 3600202027360686, 24924446019234303 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Column 4 of A318045.
LINKS
FORMULA
Empirical recurrence of order 72 (see link above)
EXAMPLE
Some solutions for n=5
..0..1..1..0. .0..0..1..1. .0..0..1..0. .0..1..0..1. .0..1..0..0
..1..0..0..1. .0..1..0..0. .0..1..1..0. .1..1..0..0. .1..1..1..1
..1..0..0..0. .1..1..0..1. .1..1..1..0. .0..0..0..1. .0..1..1..0
..1..0..1..1. .0..0..0..1. .0..0..0..1. .1..1..1..0. .0..1..0..1
..1..0..1..0. .1..0..1..0. .1..0..1..1. .0..1..0..0. .1..0..1..0
CROSSREFS
Cf. A318045.
Sequence in context: A137969 A303349 A337467 * A054419 A228115 A033888
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 13 2018
STATUS
approved

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Last modified June 18 04:26 EDT 2024. Contains 373468 sequences. (Running on oeis4.)