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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A186873 Number of (n+2)X3 0..3 arrays with every 3X3 subblock commuting with each horizontal and vertical neighbor 3X3 subblock 1
262144, 2428, 19236, 46583, 104701, 186096, 277659, 322910, 569446, 975469, 1428461, 2729288, 4782807, 7112898, 12726103, 21815463, 33093523, 58123410, 99742321, 154917607, 268187989, 458493523, 723302362, 1237486150, 2107632127 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A186881

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n)=2*a(n-1)-a(n-2)+3*a(n-3)-6*a(n-4)+3*a(n-5)+3*a(n-6)-3*a(n-7) for n>20

EXAMPLE

Some solutions for 4X3

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

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

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

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

CROSSREFS

Sequence in context: A069393 A186872 A186881 * A018867 A057445 A069279

Adjacent sequences:  A186870 A186871 A186872 * A186874 A186875 A186876

KEYWORD

nonn

AUTHOR

R. H. Hardin Feb 28 2011

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 August 20 01:14 EDT 2019. Contains 326136 sequences. (Running on oeis4.)