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A318011 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 1
4, 28, 118, 508, 2130, 8971, 37700, 158613, 667178, 2806643, 11806334, 49664719, 208919728, 878843413, 3696948061, 15551606501, 65419489183, 275194053961, 1157633112776, 4869707055676, 20484941672721, 86172090154282 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 3 of A318016.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) +5*a(n-2) +3*a(n-4) -4*a(n-5) -11*a(n-6) -6*a(n-7) -a(n-8) -4*a(n-9) -4*a(n-10) -a(n-11) for n>14
EXAMPLE
Some solutions for n=5
..0..0..1. .0..0..1. .0..1..1. .0..0..0. .0..0..0. .0..1..1. .0..0..0
..0..0..1. .1..1..1. .0..1..1. .1..0..0. .1..1..0. .0..1..0. .0..0..1
..0..0..1. .1..1..0. .0..0..0. .1..0..0. .1..1..1. .1..0..0. .0..1..1
..0..0..1. .0..0..1. .0..0..0. .1..1..1. .1..1..1. .1..0..0. .1..1..1
..1..0..1. .0..1..1. .1..0..1. .0..1..1. .0..0..0. .1..1..1. .1..1..0
CROSSREFS
Cf. A318016.
Sequence in context: A183469 A058227 A296392 * A328685 A212900 A196514
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 12 2018
STATUS
approved

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Last modified February 23 14:24 EST 2024. Contains 370283 sequences. (Running on oeis4.)