|
Search: id:A141110
|
|
|
| A141110 |
|
Number of cycles and fixed points in the permutation (n, n-2, n-4, ..., 1, ..., n-3, n-1). |
|
+0
1
|
|
| 1, 1, 1, 2, 1, 1, 3, 2, 1, 3, 1, 2, 3, 1, 3, 4, 3, 1, 3, 2, 3, 5, 1, 2, 5, 1, 3, 4, 1, 1, 7, 6, 1, 3, 1, 4, 5, 3, 1, 4, 1, 7, 3, 4, 5, 7, 3, 2, 7, 1, 1, 8, 1, 3, 3, 4, 3, 7, 5, 2, 5, 3, 9, 10, 1, 5, 7, 2, 1, 3, 3, 6, 5, 1, 5, 8, 7, 3, 3, 4, 1, 9, 1, 2, 11
(list; graph; listen)
|
|
|
OFFSET
|
1,4
|
|
|
COMMENT
|
The above permutation can be generated by taking S_n: (1, 2, ..., n) and reversing the first two, first three and so on till first n, elements in sequence. Interestingly this permutation orbit has length given by: A003558
|
|
LINKS
|
T. D. Noe, Table of n, a(n) for n = 1..10000
|
|
EXAMPLE
|
a(20) = 2, since (20, 18, 16, 14, 12, 10, 8, 6, 4, 2, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19) has two cycles (1, 20, 19, 17, 13, 5, 12, 3, 16, 11) and (2, 18, 15, 9, 4, 14, 7, 8, 6, 10)
|
|
CROSSREFS
|
Cf. A003558.
Sequence in context: A165162 A125106 A152538 this_sequence A025831 A079673 A124829
Adjacent sequences: A141107 A141108 A141109 this_sequence A141111 A141112 A141113
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Ramasamy Chandramouli (thedavinci(AT)gmail.com), Jun 05 2008
|
|
|
Search completed in 0.002 seconds
|
