login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A213608 Number of n X n binary matrices with zero diagonal and x(i,j)+x(j,k)+x(k,i) not equal to one for i,j,k all different 0
1, 4, 25, 175, 1572, 19285, 321925, 7695406, 271013005 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A084210 A093683 A006348 * A324169 A213231 A051820

Adjacent sequences:  A213605 A213606 A213607 * A213609 A213610 A213611

KEYWORD

nonn

AUTHOR

R. H. Hardin Jun 16 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 23 03:15 EST 2022. Contains 350504 sequences. (Running on oeis4.)