Number of permutations of 1..n with both permutation and its inverse having exactly 4 maxima.
A180394
Number of permutations of 1..n with both permutation and its inverse having exactly 4 maxima.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =19a(7) =1784a(8) =55092a(9) =952640a(10) =11346508a(11) =103655440a(12) =774656344a(13) =4940080352a(14) =27682462431
External references
- oeis: A180394