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!)
A210897 Number of (2n)X(2n) 0..2 symmetric matrices with every element equal to two horizontal and vertical neighbors, and new values 0..2 introduced in lower triangle row major order 0
1, 3, 35, 792, 34547, 2902490, 468761578, 145469326676, 86673425993599 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..9.

EXAMPLE

All solutions for n=2

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

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

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

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

CROSSREFS

Sequence in context: A093531 A129505 A185752 * A267221 A135516 A231644

Adjacent sequences:  A210894 A210895 A210896 * A210898 A210899 A210900

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 January 24 07:18 EST 2020. Contains 331189 sequences. (Running on oeis4.)