Rencontres numbers: number of permutations of [n] with exactly 3 fixed points.
A000449
Rencontres numbers: number of permutations of [n] with exactly 3 fixed points.
Terms
- a(0) =1a(1) =0a(2) =10a(3) =40a(4) =315a(5) =2464a(6) =22260a(7) =222480a(8) =2447445a(9) =29369120a(10) =381798846a(11) =5345183480a(12) =80177752655
External references
- oeis: A000449