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!)
A192644 Number of n X n symmetric 0..7 arrays with each element equal to at least one horizontal or vertical neighbor and any new values 0..7 introduced in lower triangular row major order. 0
0, 1, 5, 137, 17687, 14743487, 78148721677, 2854620794876552 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

Some solutions for 6 X 6 containing a 7:

..0..0..1..1..5..5....0..0..2..2..5..5....0..0..0..2..4..4....0..0..0..2..5..7

..0..0..2..3..6..6....0..1..1..3..5..5....0..0..1..2..5..5....0..0..1..2..5..7

..1..2..2..3..4..5....2..1..3..3..6..6....0..1..1..3..6..7....0..1..1..3..3..7

..1..3..3..4..4..5....2..3..3..4..4..4....2..2..3..3..6..7....2..2..3..4..4..6

..5..6..4..4..4..7....5..5..6..4..7..7....4..5..6..6..4..4....5..5..3..4..6..6

..5..6..5..5..7..7....5..5..6..4..7..7....4..5..7..7..4..4....7..7..7..6..6..6

CROSSREFS

Sequence in context: A192641 A192642 A192643 * A134766 A224826 A122911

Adjacent sequences:  A192641 A192642 A192643 * A192645 A192646 A192647

KEYWORD

nonn,more

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 July 23 14:44 EDT 2021. Contains 346259 sequences. (Running on oeis4.)