Number T(n,k) of permutations p of [n] having at least one index i with |p(i)-i| = k; triangle T(n,k), n>=1, 0<=k<=n-1, read by rows.
A306506
Number T(n,k) of permutations p of [n] having at least one index i with |p(i)-i| = k; triangle T(n,k), n>=1, 0<=k<=n-1, read by rows.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =4a(4) =4a(5) =3a(6) =15a(7) =19a(8) =15a(9) =10a(10) =76a(11) =99a(12) =86a(13) =67a(14) =42a(15) =455a(16) =603a(17) =544a(18) =455a(19) =358a(20) =216a(21) =3186a(22) =4248a(23) =3934a(24) =3486a(25) =2921a(26) =2250a(27) =1320a(28) =25487a(29) =34115
External references
- oeis: A306506