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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
OFFSET
0,3
COMMENTS
It seems that there is no known g.f.
LINKS
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
KEYWORD
nonn,more
AUTHOR
N. J. A. Sloane, Aug 30 2015
STATUS
approved