login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A206320 Number of (n+1) X 2 0..3 arrays with every 2 X 3 or 3 X 2 subblock having exactly three clockwise edge increases. 1
256, 1344, 10504, 83088, 673124, 5432884, 43848120, 353716772, 2853265228, 23015359308, 185649551836, 1497511097624, 12079428217088, 97436737226308, 785957567591456, 6339798686936496, 51138953368767152, 412504036786299552 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A206327.

LINKS

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

FORMULA

Empirical: a(n) = 9*a(n-1) - 5*a(n-2) - 26*a(n-3) + 42*a(n-4) + 19*a(n-5) + 42*a(n-6) + 14*a(n-7) for n>8.

Empirical g.f.: 4*x*(64 - 240*x - 78*x^2 + 482*x^3 + 511*x^4 + 500*x^5 + 154*x^6 + 8*x^7) / (1 - 9*x + 5*x^2 + 26*x^3 - 42*x^4 - 19*x^5 - 42*x^6 - 14*x^7). - Colin Barker, Jun 15 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Cf. A206327.

Sequence in context: A231943 A206327 A242257 * A237315 A237309 A188865

Adjacent sequences:  A206317 A206318 A206319 * A206321 A206322 A206323

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 06 2012

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 26 18:22 EST 2021. Contains 340442 sequences. (Running on oeis4.)