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A301879
Number of nX3 0..1 arrays with every element equal to 0, 1 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.
1
3, 10, 29, 95, 289, 917, 2841, 8921, 27801, 87009, 271657, 849313, 2653273, 8292465, 25910729, 80972065, 253021369, 790675217, 2470747561, 7720841601, 24126677401, 75393222129, 235594969737, 736207657313, 2300563919993, 7188999803345
OFFSET
1,1
COMMENTS
Column 3 of A301884.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +6*a(n-2) +2*a(n-3)
EXAMPLE
Some solutions for n=5
..0..1..0. .0..1..0. .0..1..0. .0..1..0. .0..1..0. .0..0..0. .0..1..0
..0..0..1. .0..0..0. .1..0..1. .0..1..0. .0..1..1. .0..1..1. .0..1..0
..0..1..0. .1..1..0. .1..0..1. .0..1..0. .0..0..0. .0..0..1. .1..0..0
..0..1..0. .0..1..0. .1..0..1. .1..0..0. .0..1..1. .1..0..1. .0..1..1
..0..1..0. .1..0..1. .1..0..1. .0..1..1. .0..0..1. .1..0..1. .0..0..1
CROSSREFS
Cf. A301884.
Sequence in context: A361365 A147363 A147226 * A147062 A293155 A146384
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 28 2018
STATUS
approved