Number of permutations p of [n] having at least one index i with |p(i)-i| = 1.
A306511
Number of permutations p of [n] having at least one index i with |p(i)-i| = 1.
Terms
- a(0) =0a(1) =0a(2) =1a(3) =4a(4) =19a(5) =99a(6) =603a(7) =4248a(8) =34115a(9) =307875a(10) =3085203a(11) =33993870a(12) =408482695a(13) =5316309607a(14) =74499953255
External references
- oeis: A306511