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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A208561 Number of nX2 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward or left-upward diagonal neighbors 1
2, 10, 68, 464, 3168, 21632, 147712, 1008640, 6887424, 47030272, 321142784, 2192900096, 14974058496, 102249267200, 698201669632, 4767619219456, 32555340398592, 222301769433088, 1517971432275968, 10365357302743040 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A208567

LINKS

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

FORMULA

Empirical: a(n) = 8*a(n-1) -8*a(n-2) for n>3

EXAMPLE

Some solutions for n=4

..0..1....0..0....0..1....0..0....0..0....0..0....0..0....0..0....0..1....0..0

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

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

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

CROSSREFS

Sequence in context: A245000 A108397 A049036 * A152620 A152621 A147725

Adjacent sequences:  A208558 A208559 A208560 * A208562 A208563 A208564

KEYWORD

nonn

AUTHOR

R. H. Hardin Feb 28 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified September 26 15:27 EDT 2017. Contains 292531 sequences.