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A296391
Number of nX3 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 1 or 3 neighboring 1s.
1
3, 11, 36, 115, 387, 1280, 4237, 14026, 46454, 153800, 509255, 1686210, 5583282, 18486920, 61212645, 202682982, 671109638, 2222130975, 7357763936, 24362510288, 80667430752, 267100323021, 884403804216, 2928375674093, 9696231573791
OFFSET
1,1
COMMENTS
Column 3 of A296396.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +4*a(n-2) +2*a(n-3) -3*a(n-4) -2*a(n-5) +7*a(n-6) +4*a(n-7) +a(n-8) -14*a(n-9) +10*a(n-11) -3*a(n-12) -2*a(n-13) +a(n-14)
EXAMPLE
Some solutions for n=5
..1..0..1. .0..0..0. .1..1..0. .1..1..0. .0..0..0. .1..1..0. .1..1..1
..1..0..1. .0..0..0. .0..0..0. .0..0..0. .1..1..0. .0..0..0. .0..1..1
..0..0..0. .0..0..0. .0..1..0. .0..0..0. .0..0..0. .1..1..0. .0..0..1
..1..1..0. .0..1..1. .0..1..1. .0..1..0. .0..0..0. .0..0..1. .1..1..1
..0..0..0. .0..0..0. .1..0..0. .0..1..0. .0..1..1. .0..1..0. .0..0..1
CROSSREFS
Cf. A296396.
Sequence in context: A297577 A119126 A119088 * A305132 A291413 A347829
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 11 2017
STATUS
approved