Number of permutations of 1..n with number of rises (p(i+1)>p(i)) the same as number of rises in the inverse permutation.

A180389

Number of permutations of 1..n with number of rises (p(i+1)>p(i)) the same as number of rises in the inverse permutation.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =22a(5) =96a(6) =492a(7) =2952a(8) =20588a(9) =164990a(10) =1497740a(11) =15187692a(12) =169974040a(13) =2078905752a(14) =27567259896a(15) =393759207372

External references