A289652 Catalan numbers - 2 (A120304) with first three terms changed to 1,1,1.

1, 1, 1, 3, 12, 40, 130, 427, 1428, 4860, 16794, 58784, 208010, 742898, 2674438, 9694843, 35357668, 129644788, 477638698, 1767263188, 6564120418, 24466267018, 91482563638, 343059613648, 1289904147322, 4861946401450, 18367353072150, 69533550916002, 263747951750358

Offset: 1

Author

N. J. A. Sloane, Jul 09 2017

Keywords

• nonn

Comments

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

Links

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

Crossrefs

A variant of A120304.

All of A000108, A001453, A246604, A273526, A120304, A289615, A289616, A289652, A289653, A289654 are very similar sequences.

Programs

Mathematica

Join[{1,1,1},CatalanNumber[Range[3,30]]-2] (* Paolo Xausa, Dec 08 2023 *)