Rencontres numbers: number of permutations of [n] with exactly 4 fixed points.

A000475

Rencontres numbers: number of permutations of [n] with exactly 4 fixed points.

Terms

    a(0) =1a(1) =0a(2) =15a(3) =70a(4) =630a(5) =5544a(6) =55650a(7) =611820a(8) =7342335a(9) =95449640a(10) =1336295961a(11) =20044438050a(12) =320711010620

External references