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A297333
Number of n X 3 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 0 or 2 neighboring 1s.
1
5, 22, 96, 421, 1847, 8105, 35568, 156089, 684994, 3006088, 13192185, 57893767, 254066201, 1114966916, 4893020877, 21472971950, 94233917248, 413544579709, 1814836148199, 7964389829833, 34951643113640, 153384927463937
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) - 2*a(n-2) - 3*a(n-3).
Empirical g.f.: x*(5 - 3*x - 4*x^2) / (1 - 5*x + 2*x^2 + 3*x^3). - Colin Barker, Feb 26 2019
EXAMPLE
Some solutions for n=5:
..0..0..1. .0..0..0. .0..0..1. .1..0..1. .0..0..0. .0..1..0. .0..0..0
..1..0..1. .0..0..1. .0..0..0. .1..0..1. .1..0..1. .0..1..1. .0..0..0
..0..0..1. .1..0..1. .1..0..0. .0..0..0. .0..0..1. .1..1..0. .0..1..0
..1..0..1. .0..0..0. .1..0..0. .0..1..1. .1..0..1. .0..1..0. .0..0..1
..0..0..0. .0..0..1. .1..0..1. .1..1..0. .0..0..1. .0..0..1. .1..0..1
CROSSREFS
Column 3 of A297338.
Sequence in context: A266430 A083586 A200676 * A129158 A342554 A129164
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 28 2017
STATUS
approved