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A300375
Number of nX3 0..1 arrays with every element equal to 0, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
1
1, 2, 4, 11, 8, 58, 131, 306, 936, 2435, 6683, 18093, 49663, 134666, 367314, 1002020, 2728817, 7439403, 20275261, 55264984, 150614904, 410527337, 1118909399, 3049617734, 8311952136, 22654640136, 61746476769, 168293237171, 458692748831
OFFSET
1,2
COMMENTS
Column 3 of A300380.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-2) +9*a(n-3) +9*a(n-4) +3*a(n-5) -8*a(n-6) -a(n-7) -18*a(n-8) -24*a(n-9) -45*a(n-10) -10*a(n-11) -15*a(n-12) +39*a(n-13) -21*a(n-14) +9*a(n-15) -7*a(n-16) -13*a(n-17) +14*a(n-18) -5*a(n-19) +3*a(n-20) -2*a(n-22) +a(n-23) for n>25
EXAMPLE
Some solutions for n=5
..0..0..1. .0..1..1. .0..0..0. .0..0..0. .0..0..1. .0..0..1. .0..0..1
..0..1..1. .1..0..1. .0..1..0. .0..1..0. .0..1..1. .0..1..1. .0..1..1
..0..0..0. .1..1..1. .0..0..0. .1..1..0. .0..0..0. .0..0..0. .1..0..1
..0..1..0. .0..0..1. .1..1..0. .0..0..1. .0..1..0. .1..1..0. .1..1..0
..0..0..0. .0..1..1. .1..0..0. .0..1..1. .0..0..1. .1..0..0. .1..0..0
CROSSREFS
Cf. A300380.
Sequence in context: A246164 A124183 A218643 * A075488 A363702 A136995
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 04 2018
STATUS
approved