|
|
A200424
|
|
Number of -2..2 arrays x(0..n+2) of n+3 elements with zero sum and no two or three adjacent elements summing to zero
|
|
1
|
|
|
20, 80, 212, 594, 1928, 6780, 23674, 80750, 271000, 909282, 3082640, 10545846, 36174576, 123964062, 424595930, 1456168762, 5004245744, 17226485764, 59361633214, 204702938074, 706403203606, 2439664629760, 8432567247356
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
EXAMPLE
|
Some solutions for n=3
.-2....2...-1...-1....2...-2....0...-1....2....2....2...-1....1...-1....1....0
.-2...-1....0...-2....1...-2...-1...-2...-1....1....1....0....2....0....0...-1
..0...-2....2....0...-2....1....2...-2....2....0....0...-2....1...-2...-2....0
..1...-2....0....1....0....2....1....1....0...-2...-2...-1...-2....0...-2...-2
..2....1....1....1...-1....0....0....2...-1...-2....0....2...-1....1....1....1
..1....2...-2....1....0....1...-2....2...-2....1...-1....2...-1....2....2....2
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|