a(n) is the number of permutations of length n that avoid the pattern 321 and the mesh pattern (12, 174) or the same sequence for the mesh pattern (12, 234).
A289587
a(n) is the number of permutations of length n that avoid the pattern 321 and the mesh pattern (12, 174) or the same sequence for the mesh pattern (12, 234).
Terms
- a(0) =1a(1) =1a(2) =1a(3) =3a(4) =6a(5) =18a(6) =47a(7) =139a(8) =405a(9) =1225a(10) =3740a(11) =11602a(12) =36357a(13) =115049a(14) =366969a(15) =1178791a(16) =3809802
External references
- oeis: A289587