Number of Dumont permutations of the first kind of length 2n avoiding the patterns 2413 and 4132. Also number of Dumont permutations of the first kind of length 2n avoiding the patterns 1423 and 3142.
A125188
Number of Dumont permutations of the first kind of length 2n avoiding the patterns 2413 and 4132. Also number of Dumont permutations of the first kind of length 2n avoiding the patterns 1423 and 3142.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =12a(4) =54a(5) =259a(6) =1294a(7) =6655a(8) =34986a(9) =187149a(10) =1015407a(11) =5574829a(12) =30915904a(13) =172933249a(14) =974605751a(15) =5528804444a(16) =31546576802a(17) =180931023589
External references
- oeis: A125188