|
| |
|
|
A177560
|
|
Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, down, up.
|
|
0
|
|
|
|
1, 6, 84, 2054, 78231, 4290094, 320821079, 31414709469, 3903342922319, 600255674485509, 111949642485388109, 24900064681761042208, 6512262064364063116565, 1978717544093002418592533
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
LINKS
|
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
|
|
|
EXTENSIONS
|
|
|
|
STATUS
|
approved
|
| |
|
|
