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!)
A199893 Number of -3..3 arrays x(0..n-1) of n elements with zero sum, and adjacent elements not both strictly positive and not both strictly negative 1
1, 7, 25, 111, 461, 2035, 8823, 39053, 172355, 767425, 3420017, 15311495, 68665323, 308805403, 1391091909, 6278869703, 28381760049, 128482271031, 582346682067, 2642616002605, 12004291295381, 54583533395613, 248409301882015 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 3 of A199898

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

EXAMPLE

Some solutions for n=6

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

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

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

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

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

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

CROSSREFS

Sequence in context: A327627 A110240 A266810 * A129791 A216688 A141626

Adjacent sequences:  A199890 A199891 A199892 * A199894 A199895 A199896

KEYWORD

nonn

AUTHOR

R. H. Hardin Nov 11 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 February 26 16:33 EST 2020. Contains 332284 sequences. (Running on oeis4.)