Number of permutations of [2n] with exactly n fixed points.
A281262
Number of permutations of [2n] with exactly n fixed points.
Terms
- a(0) =1a(1) =0a(2) =6a(3) =40a(4) =630a(5) =11088a(6) =244860a(7) =6362928a(8) =190900710a(9) =6490575520a(10) =246642054516
External references
- oeis: A281262