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A208088
Number of 7 X (n+1) 0..1 arrays with every 2 X 2 subblock having the same number of equal edges as its horizontal neighbors and a different number from its vertical neighbors, and new values 0..1 introduced in row major order.
1
108, 180, 288, 468, 756, 1224, 1980, 3204, 5184, 8388, 13572, 21960, 35532, 57492, 93024, 150516, 243540, 394056, 637596, 1031652, 1669248, 2700900, 4370148, 7071048, 11441196, 18512244, 29953440, 48465684, 78419124, 126884808
OFFSET
1,1
COMMENTS
Row 6 of A208085.
LINKS
FORMULA
Empirical: a(n) = a(n-1) + a(n-2).
Conjectures from Colin Barker, Jun 27 2018: (Start)
G.f.: 36*x*(3 + 2*x) / (1 - x - x^2).
a(n) = (9*2^(2-n)*((1-sqrt(5))^n*(-2+sqrt(5)) + (1+sqrt(5))^n*(2+sqrt(5)))) / sqrt(5).
(End)
EXAMPLE
Some solutions for n=4:
..0..0..0..1..0....0..1..0..1..1....0..0..0..0..0....0..0..0..1..0
..0..1..0..1..0....0..0..0..0..0....0..1..0..1..0....1..1..1..1..1
..1..0..1..0..1....0..0..0..0..0....1..0..1..0..1....1..1..1..1..1
..1..0..1..0..1....1..0..1..0..1....0..0..0..0..0....1..0..1..0..1
..0..1..0..1..0....0..1..0..1..0....0..0..0..0..0....0..1..0..1..0
..1..1..1..1..1....0..0..0..0..0....0..1..0..1..0....0..1..0..1..0
..1..1..1..1..1....0..0..0..0..0....1..0..1..0..1....1..0..1..0..1
CROSSREFS
Cf. A208085.
Sequence in context: A039601 A330851 A245032 * A323548 A338382 A338384
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 23 2012
STATUS
approved