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A269181
Number of nX3 0..3 arrays with some element plus some horizontally, diagonally, antidiagonally or vertically adjacent neighbor totalling three exactly once.
1
24, 384, 5888, 80112, 1031344, 12791896, 154606864, 1833130768, 21416076480, 247279304248, 2828051682752, 32088228414160, 361662427633424, 4053056289550296, 45198059875209904, 501865175240768976
OFFSET
1,1
COMMENTS
Column 3 of A269186.
LINKS
FORMULA
Empirical: a(n) = 22*a(n-1) -131*a(n-2) +88*a(n-3) +221*a(n-4) -154*a(n-5) -101*a(n-6) +44*a(n-7) -4*a(n-8) for n>9
EXAMPLE
Some solutions for n=4
..1..2..0. .0..0..0. .3..1..2. .1..1..0. .1..0..1. .3..0..1. .3..1..2
..0..0..2. .2..0..2. .3..3..3. .3..3..1. .0..1..0. .1..1..0. .1..3..3
..2..0..0. .2..2..2. .1..1..1. .2..3..1. .1..0..2. .1..1..1. .3..3..2
..2..2..2. .3..0..2. .1..1..0. .3..3..1. .1..0..0. .1..0..0. .2..2..3
CROSSREFS
Cf. A269186.
Sequence in context: A228406 A087292 A081138 * A266185 A114631 A020782
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 20 2016
STATUS
approved