login
This site is supported by donations to The OEIS Foundation.

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A221853 Number of 2 X n arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, without consecutive moves in the same direction. 1
1, 31, 302, 3437, 37155, 406612, 4434129, 48397883, 528123314, 5763315281, 62892896491, 686329748776, 7489683895265, 81732408497079, 891918279715066, 9733204380907645, 106215187016111667, 1159090627331995148 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row 2 of A221852.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..37

FORMULA

Empirical: a(n) = 13*a(n-1) - 14*a(n-2) - 113*a(n-3) + 189*a(n-4) - 10*a(n-5) - 42*a(n-6) + 18*a(n-7) - 2*a(n-8).

Empirical g.f.: x*(1 + 18*x - 87*x^2 + 58*x^3 + 16*x^4 - 8*x^5 - 2*x^6) / (1 - 13*x + 14*x^2 + 113*x^3 - 189*x^4 + 10*x^5 + 42*x^6 - 18*x^7 + 2*x^8). - Colin Barker, Aug 11 2018

EXAMPLE

Some solutions for n=3:

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

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

CROSSREFS

Cf. A221852.

Sequence in context: A279980 A001298 A027841 * A000500 A141912 A147297

Adjacent sequences:  A221850 A221851 A221852 * A221854 A221855 A221856

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 27 2013

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 17 23:15 EST 2019. Contains 319251 sequences. (Running on oeis4.)