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

A289654

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

Terms

    a(0) =1a(1) =1a(2) =1a(3) =3a(4) =13a(5) =40a(6) =130a(7) =427a(8) =1428a(9) =4860a(10) =16794

External references