A289588 Related to number of mesh patterns of length 2 that avoid the pattern 321.

1, 1, 1, 2, 4, 11, 34, 110, 365, 1234, 4237

Offset

1,4

Links

Table of n, a(n) for n=1..11.

Murray Tannock, Equivalence classes of mesh patterns with a dominating pattern, MSc Thesis, Reykjavik Univ., May 2016. See Appendix B2.

Formula

G.f.: (x^4+x^3-x^2)*C(x)/(x-1) - (x^4-x^2+x)/(x-1) where C(x) is the g.f. for the Catalan numbers (A000108) (conjectured). - Michael D. Weiner, Aug 08 2019

Crossrefs

Sequence in context: A369843 A099215 A089407 * A362638 A344489 A238425

Adjacent sequences: A289585 A289586 A289587 * A289589 A289590 A289591

Keyword

nonn,more

Author

N. J. A. Sloane, Jul 08 2017

Status

approved