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!)
A193500 Number of n X n symmetric 0..3 arrays with no element equal to the product mod 4 of any two of its horizontal and vertical neighbors 0
4, 30, 476, 16922, 1328430, 224738251, 82830799570, 66307508721755, 115414300257319497, 435721788093736397288, 3576788708181112341917385, 63678865525598948282213562255, 2464034493065067438484568541197974 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

EXAMPLE

Some solutions for 4X4

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

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

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

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

CROSSREFS

Sequence in context: A326205 A290058 A168129 * A163885 A120338 A064050

Adjacent sequences:  A193497 A193498 A193499 * A193501 A193502 A193503

KEYWORD

nonn

AUTHOR

R. H. Hardin Jul 29 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 September 18 14:52 EDT 2021. Contains 347527 sequences. (Running on oeis4.)