A289653 Catalan numbers - 2 (A120304) with first four terms changed to 1,1,1,4.

1, 1, 1, 4, 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

1,4

Comments

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

Links

Table of n, a(n) for n=1..29.

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

Mathematica

Join[{1, 1, 1, 4}, CatalanNumber[Range[4, 30]]-2] (* Paolo Xausa, Dec 08 2023 *)

Crossrefs

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

Sequence in context: A152174 A087206 A275863 * A081875 A102433 A221652

Adjacent sequences: A289650 A289651 A289652 * A289654 A289655 A289656

Keyword

nonn

Author

N. J. A. Sloane, Jul 09 2017

Status

approved