A289453 Related to number of mesh patterns of length 2 that avoid the pattern 321.

1, 1, 1, 2, 5, 13, 36, 103, 303, 910, 2779

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

Conjectured g.f.: (2-sqrt(2))*x/2+x/sqrt(2)*C(sqrt(2)*x/(x^2+(2*sqrt(2)-1)*x+1)), where C(x) is the g.f. for the Catalan numbers, A000108. - Michael D. Weiner, Jul 20 2022

Crossrefs

Cf. A000108.

Sequence in context: A370168 A099164 A358460 * A339290 A036765 A246555

Adjacent sequences: A289450 A289451 A289452 * A289454 A289455 A289456

Keyword

nonn,more

Author

N. J. A. Sloane, Jul 08 2017

Status

approved