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!)
A201839 Number of zero-sum n X n -1..1 arrays with every element equal to at least one horizontal or vertical neighbor 0
0, 5, 125, 54773, 109797321, 1759241274383 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Diagonal of A201847

LINKS

Table of n, a(n) for n=1..6.

EXAMPLE

Some solutions for n=4

.-1..1..1..1...-1.-1..1..0...-1.-1..1..1...-1.-1.-1.-1...-1..1.-1.-1

.-1.-1.-1..1...-1..1..1..0....0.-1..0..0....0..1..0..0...-1..1..1.-1

..1.-1..1.-1....0..0.-1.-1....0..1..1..0....0..1.-1.-1....0..0..0..0

..1.-1..1.-1....1..1..0..0....0..1.-1.-1....1..1..1..1....0..1..1..0

CROSSREFS

Sequence in context: A109345 A194502 A229868 * A234609 A278080 A156956

Adjacent sequences:  A201836 A201837 A201838 * A201840 A201841 A201842

KEYWORD

nonn

AUTHOR

R. H. Hardin Dec 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 October 20 08:19 EDT 2021. Contains 348099 sequences. (Running on oeis4.)