a(n) is the number of permutations of length n that avoid the pattern 321 and the mesh pattern (12, 277) or the same sequence for the mesh pattern (12, 337).
A289604
a(n) is the number of permutations of length n that avoid the pattern 321 and the mesh pattern (12, 277) or the same sequence for the mesh pattern (12, 337).
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =6a(5) =25a(6) =96a(7) =357a(8) =1289a(9) =4587a(10) =16258a(11) =57728a(12) =205921a(13) =738751a(14) =2666184a(15) =9678385a(16) =35324813a(17) =129579151a(18) =477507510a(19) =1767000912a(20) =6563595981a(21) =24465218275a(22) =91480466300a(23) =343055419138
External references
- oeis: A289604