login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A217808
Number of alternating permutations on 2n letters that avoid a certain pattern of length 4 (see Lewis, 2012, Appendix, for precise definition).
0
1, 5, 42, 453, 5651, 77498, 1135828, 17485309, 279540684
(
list
;
graph
;
refs
;
listen
;
history
;
text
;
internal format
)
OFFSET
1,2
LINKS
Table of n, a(n) for n=1..9.
J. B. Lewis,
Pattern Avoidance for Alternating Permutations and Reading Words of Tableaux
, Ph. D. Dissertation, Department of Mathematics, MIT, 2012.
CROSSREFS
Cf.
A181197
,
A217799
-
A217830
.
Sequence in context:
A327272
A024492
A217805
*
A217810
A151334
A005789
Adjacent sequences:
A217805
A217806
A217807
*
A217809
A217810
A217811
KEYWORD
nonn
,
more
AUTHOR
N. J. A. Sloane
, Oct 12 2012
EXTENSIONS
a(7)-a(9) from
Lars Blomberg
, Feb 17 2018
STATUS
approved
Lookup
|
Welcome
|
Wiki
|
Register
|
Music
|
Plot 2
|
Demos
|
Index
|
Browse
|
More
|
WebCam
Contribute new seq. or comment
|
Format
|
Style Sheet
|
Transforms
|
Superseeker
|
Recents
The OEIS Community
| Maintained by
The OEIS Foundation Inc.
License Agreements, Terms of Use, Privacy Policy.
.
Last modified March 29 02:23 EDT 2024. Contains 371264 sequences. (Running on oeis4.)