Number of permutations of 1..n with both permutation and its inverse having exactly 3 maxima.
A180393
Number of permutations of 1..n with both permutation and its inverse having exactly 3 maxima.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =3a(5) =118a(6) =1719a(7) =15080a(8) =96080a(9) =489240a(10) =2106564a(11) =7954480a(12) =27009063a(13) =83965806a(14) =242238695
External references
- oeis: A180393