|
Search: id:A086852
|
|
|
| A086852 |
|
Number of permutations of length n with exactly 1 rising or falling succession. |
|
+0
10
|
|
| 0, 0, 2, 4, 10, 40, 230, 1580, 12434, 110320, 1090270, 11876980, 141373610, 1825321016, 25405388150, 379158271420, 6039817462210, 102278890975360, 1834691141852174, 34752142215026180, 693126840194499290, 14519428780464454600, 318705819455462421670
(list; graph; listen)
|
|
|
OFFSET
|
0,3
|
|
|
COMMENT
|
Permutations of 12...n such that exactly one of the following occur: 12, 23, ..., (n-1)n, 21, 32, ..., n(n-1).
|
|
REFERENCES
|
F. N. David, M. G. Kendall and D. E. Barton, Symmetric Function and Allied Tables, Cambridge, 1966, p. 263.
J. Riordan, A recurrence for permutations without rising or falling successions. Ann. Math. Statist. 36 (1965), 708-710.
|
|
FORMULA
|
Coefficient of t^1 in S[n](t) defined in A002464.
|
|
CROSSREFS
|
Cf. A002464, A086853, A086854, A000349, A001267. Twice A000130. A diagonal of A001100.
Sequence in context: A109460 A108801 A111022 this_sequence A084737 A153757 A159860
Adjacent sequences: A086849 A086850 A086851 this_sequence A086853 A086854 A086855
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
N. J. A. Sloane (njas(AT)research.att.com), Aug 19 2003
|
|
|
Search completed in 0.002 seconds
|
