Number of permutations of [n] having exactly one pair of integers i<j in [n] such that their cycle minima have opposite sorting order.
A381539
Number of permutations of [n] having exactly one pair of integers i<j in [n] such that their cycle minima have opposite sorting order.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =1a(4) =5a(5) =21a(6) =89a(7) =408a(8) =2106a(9) =12529a(10) =86579a(11) =691287a(12) =6296333a(13) =64454418a(14) =731532528a(15) =9101244205a(16) =122993164505
External references
- oeis: A381539