|
| |
|
|
A217806
|
|
Number of alternating permutations on 2n letters that avoid a certain pattern of length 4 (see Lewis, 2012, Appendix, for precise definition).
|
|
0
|
| |
|
|
|
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: A002895 A294189 A141004 * A152410 A177403 A196523
Adjacent sequences: A217803 A217804 A217805 * A217807 A217808 A217809
|
|
|
KEYWORD
|
nonn,more
|
|
|
AUTHOR
|
N. J. A. Sloane, Oct 12 2012
|
|
|
EXTENSIONS
|
a(7)-a(9) from Lars Blomberg, Feb 17 2018
|
|
|
STATUS
|
approved
|
| |
|
|
