Number of permutations of [n] such that the minimal element of each cycle is also its length.

A364406

Number of permutations of [n] such that the minimal element of each cycle is also its length.

Terms

    a(0) =1a(1) =1a(2) =0a(3) =1a(4) =0a(5) =0a(6) =6a(7) =6a(8) =0a(9) =0a(10) =720a(11) =2160a(12) =9360a(13) =19440a(14) =30240a(15) =3659040a(16) =21772800a(17) =228614400a(18) =1632960000a(19) =11125900800a(20) =73025971200

External references