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 A205635 Number of (n+1)X2 0..3 arrays with every 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward and upward neighbors. 1
 256, 2320, 21416, 198688, 1843744, 17111320, 158804736, 1473828208, 13678225256, 126944238720, 1178138077344, 10934009198136, 101475844940512, 941772325426928, 8740357030533704, 81117101420015392, 752827845002975520 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 1 of A205642. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 16*a(n-1) -64*a(n-2) -46*a(n-3) +680*a(n-4) -1040*a(n-5) -73*a(n-6) +912*a(n-7) -228*a(n-8) -176*a(n-9) +20*a(n-10). EXAMPLE Some solutions for n=4: ..1..0....0..0....3..3....3..3....1..2....3..2....3..0....1..1....3..3....1..1 ..0..0....2..1....3..1....1..1....0..2....1..1....0..1....0..1....0..1....3..2 ..0..3....1..1....3..1....3..0....0..1....3..2....1..2....1..1....2..3....3..0 ..1..2....1..0....3..3....1..0....0..3....3..3....3..3....2..1....2..0....1..1 ..0..3....0..0....3..1....0..0....2..2....0..0....3..2....0..0....2..2....1..2 CROSSREFS Sequence in context: A206102 A014713 A205642 * A205027 A207300 A205020 Adjacent sequences:  A205632 A205633 A205634 * A205636 A205637 A205638 KEYWORD nonn AUTHOR R. H. Hardin, Jan 29 2012 STATUS approved

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Last modified December 8 17:01 EST 2021. Contains 349596 sequences. (Running on oeis4.)