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!)
A192641 Number of n X n symmetric 0..4 arrays with each element equal to at least one horizontal or vertical neighbor and any new values 0..4 introduced in lower triangular row major order 0
0, 1, 5, 137, 17487, 11679460, 29893061411, 272547393058796, 8435849125548477470, 886985453412974633027297 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..10.

EXAMPLE

Some solutions for 6X6 containing a 4

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

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

..0..0..1..1..4..4....0..0..0..1..2..1....0..0..0..2..1..2....0..0..0..2..2..3

..0..2..1..3..3..4....1..1..1..1..2..1....1..2..2..1..1..2....0..1..2..1..1..3

..0..2..4..3..3..4....2..3..2..2..2..4....1..3..1..1..4..4....2..1..2..1..1..4

..1..1..4..4..4..4....2..3..1..1..4..4....3..3..2..2..4..4....2..1..3..3..4..4

CROSSREFS

Sequence in context: A012142 A012207 A192640 * A192642 A192643 A192644

Adjacent sequences:  A192638 A192639 A192640 * A192642 A192643 A192644

KEYWORD

nonn

AUTHOR

R. H. Hardin Jul 06 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 January 28 21:04 EST 2022. Contains 350664 sequences. (Running on oeis4.)