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A205937 Number of (n+1) X 2 0..3 arrays with no 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward or upward neighbors. 1
256, 1776, 12712, 91440, 656272, 4711264, 33827496, 242859696, 1743558448, 12517828752, 89871316488, 645223555056, 4632334222640, 33257550378496, 238770342344520, 1714234994048944, 12307232871040912, 88358941969931504 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 1 of A205944.
LINKS
FORMULA
Empirical: a(n) = 16*a(n-2) + 132*a(n-3) + 626*a(n-4) + 1504*a(n-5) + 2204*a(n-6) + 2140*a(n-7) + 1011*a(n-8) + 96*a(n-9) + 80*a(n-10).
EXAMPLE
Some solutions for n=4:
..1..1....3..3....1..0....2..2....0..3....1..0....1..1....3..1....2..2....1..1
..2..0....1..1....0..0....1..0....3..0....0..1....2..0....1..1....0..2....2..1
..2..0....1..1....0..0....0..3....2..1....0..0....2..2....3..2....2..1....3..2
..1..0....2..3....1..2....0..0....3..2....3..2....1..0....0..3....1..1....1..2
..3..2....1..0....1..1....2..1....3..1....1..3....3..2....1..3....1..1....0..3
CROSSREFS
Sequence in context: A238311 A205944 A238306 * A237911 A237905 A238145
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 01 2012
STATUS
approved

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Last modified April 17 15:20 EDT 2024. Contains 371764 sequences. (Running on oeis4.)