Number A(n,k) of permutations p on [2n] satisfying p^k(i) = i for all i in [n]; square array A(n,k), n>=0, k>=0, read by antidiagonals.
A246072
Number A(n,k) of permutations p on [2n] satisfying p^k(i) = i for all i in [n]; square array A(n,k), n>=0, k>=0, read by antidiagonals.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =1a(4) =1a(5) =24a(6) =1a(7) =2a(8) =2a(9) =720a(10) =1a(11) =1a(12) =10a(13) =6a(14) =40320a(15) =1a(16) =2a(17) =10a(18) =84a(19) =24a(20) =3628800a(21) =1a(22) =1a(23) =16a(24) =108a(25) =1032a(26) =120a(27) =479001600a(28) =1a(29) =2
External references
- oeis: A246072