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A289597
Related to number of mesh patterns of length 2 that avoid the pattern 321.
0
1, 1, 1, 2, 6, 21, 75, 266, 938, 3305, 11679
OFFSET
1,4
LINKS
Murray Tannock, Equivalence classes of mesh patterns with a dominating pattern, MSc Thesis, Reykjavik Univ., May 2016. See Appendix B2.
Murray Tannock, Henning Ulfarsson, Equivalence classes of mesh patterns with a dominating pattern, arXiv:1704.07104 [math.CO], 2017-2018.
FORMULA
G.f.: x*(1-x)*C(x) + x^2*(x^2-3*x+1)/((x-1)*(2*x-1)) (conjectured), where C(x) is the g.f. for the Catalan numbers (A000108). - Michael D. Weiner, Jan 02 2019
CROSSREFS
Cf. A000108.
Sequence in context: A294815 A116751 A116823 * A116743 A294816 A263790
KEYWORD
nonn,more
AUTHOR
N. J. A. Sloane, Jul 08 2017
STATUS
approved