Number of Dumont permutations of the first kind of length 2n avoiding pattern 2143 (or pattern 3421).
A308750
Number of Dumont permutations of the first kind of length 2n avoiding pattern 2143 (or pattern 3421).
Terms
- a(0) =1a(1) =1a(2) =2a(3) =7a(4) =36a(5) =239a(6) =1892a(7) =17015a(8) =168503a(9) =1799272a(10) =20409644
External references
- oeis: A308750