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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A210896 Number of n X n 0..2 symmetric matrices with every element equal to zero or one horizontal and vertical neighbors, and new values 0..2 introduced in lower triangle row major order 0
1, 2, 20, 400, 16716, 1444348, 258951340, 96266852004, 74214689922928, 118642250445743920, 393305989512539553728, 2703723885515478100466476, 38542035415959856159523945096 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..13.

EXAMPLE

Some solutions for n=3

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

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

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

CROSSREFS

Sequence in context: A009236 A078698 A090728 * A090309 A002116 A058346

Adjacent sequences:  A210893 A210894 A210895 * A210897 A210898 A210899

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 29 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 November 15 21:37 EST 2019. Contains 329168 sequences. (Running on oeis4.)