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!)
A202246 Number of zero-sum -2..2 arrays of n elements with adjacent element differences also in -2..2 1
1, 3, 9, 31, 107, 387, 1415, 5231, 19477, 72933, 274339, 1035807, 3923229, 14900005, 56721943, 216377047, 826917803, 3165318823, 12133973901, 46575395693, 178988128029, 688588254425, 2651686966607, 10220607799703, 39426825300181 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 2 of A202252

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

EXAMPLE

Some solutions for n=10

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

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

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

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

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

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

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

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

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

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

CROSSREFS

Sequence in context: A148964 A148965 A130620 * A225340 A148966 A279971

Adjacent sequences:  A202243 A202244 A202245 * A202247 A202248 A202249

KEYWORD

nonn

AUTHOR

R. H. Hardin Dec 14 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 August 13 19:30 EDT 2020. Contains 336451 sequences. (Running on oeis4.)