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A261663 Number of equivalence classes of permutations avoiding the pattern {123}. 0
1, 1, 2, 4, 8, 19, 41, 98, 221, 526 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
COMMENTS
It seems that there is no known g.f.
LINKS
Table of n, a(n) for n=0..9.
J.-L. Baril, T. Mansour, A. Petrossian, Equivalence classes of permutations modulo excedances, Journal of Combinatorics, Volume 5 (2014), Number 4, doi:10.4310/JOC.2014.v5.n4.a4.
CROSSREFS
Sequence in context: A139784 A247235 A369683 * A199694 A037444 A151526
Adjacent sequences: A261660 A261661 A261662 * A261664 A261665 A261666
KEYWORD
nonn,more
AUTHOR
N. J. A. Sloane, Aug 30 2015
STATUS
approved

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Last modified June 11 03:41 EDT 2024. Contains 373288 sequences. (Running on oeis4.)