Number of uniquely sorted permutations of [2n+1] that avoid the patterns 231 and 4123.
A307346
Number of uniquely sorted permutations of [2n+1] that avoid the patterns 231 and 4123.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =10a(4) =36a(5) =138a(6) =553a(7) =2288a(8) =9699a(9) =41908
External references
- oeis: A307346