|
|
A183942
|
|
Number of strings of n numbers x(i) in -7..7 with sums of x(i) and of x(i)*x(i+1) both zero
|
|
0
|
|
|
1, 1, 15, 57, 1033, 6259, 80851, 844829, 10894795, 130817901, 1781556515, 23640849007, 329173058411, 4518115025537, 63025886167079
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,3
|
|
COMMENTS
|
|
|
LINKS
|
|
|
EXAMPLE
|
Some solutions for n=4
.-3....0....1...-7....0....2...-4....1...-6...-4....1....0....4....6....0....3
.-6...-1....0....0...-2....0....0....0....0....1....2...-4...-1....0....6....0
..6....0....0....0....0....0....4...-1....6....2...-2....0...-2....0....0....0
..3....1...-1....7....2...-2....0....0....0....1...-1....4...-1...-6...-6...-3
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|