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A205653 Number of (n+1)X3 0..3 arrays with every 2 X 2 subblock having the same number of clockwise edge increases as its horizontal neighbors and no 2 X 2 subblock having the same number of counterclockwise edge increases as its vertical neighbors. 1
1976, 12296, 75108, 489984, 3323532, 23019504, 162377816, 1156073240, 8289295516, 59533017872, 428906318808, 3088913281608, 22288072580932, 160654914298920, 1159724849930116, 8361789529936496, 60368998110838220 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A205659.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 60*a(n-2) +22*a(n-3) -393*a(n-4) -796*a(n-5) -3283*a(n-6) -4400*a(n-7) +12703*a(n-8) +31467*a(n-9) -4307*a(n-10) -74423*a(n-11) -49777*a(n-12) +60344*a(n-13) +59244*a(n-14) -117021*a(n-15) -209936*a(n-16) +67194*a(n-17) +403998*a(n-18) +251043*a(n-19) -196160*a(n-20) -288308*a(n-21) -24656*a(n-22) +112318*a(n-23) +44464*a(n-24) -16020*a(n-25) -9600*a(n-26) for n>31.

EXAMPLE

Some solutions for n=4:

..3..3..3....2..0..3....0..1..0....0..0..1....2..0..0....3..1..3....1..0..1

..0..1..2....3..3..3....1..1..0....1..0..0....1..2..1....3..2..0....2..0..1

..1..1..1....3..0..1....2..3..3....1..2..3....1..3..2....1..2..0....1..1..0

..2..3..0....0..3..3....2..1..0....0..2..0....2..2..2....3..3..1....2..0..0

..2..1..0....0..0..1....3..2..1....1..2..3....0..0..1....0..1..1....2..2..3

CROSSREFS

Sequence in context: A135845 A121995 A061998 * A206182 A205364 A210160

Adjacent sequences:  A205650 A205651 A205652 * A205654 A205655 A205656

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 30 2012

STATUS

approved

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Last modified September 29 10:30 EDT 2022. Contains 357088 sequences. (Running on oeis4.)