Number of permutations p of [2n+2] such that min_{j=1..2n+2} |p(j)-j| = n.
A306545
Number of permutations p of [2n+2] such that min_{j=1..2n+2} |p(j)-j| = n.
Terms
- a(0) =1a(1) =8a(2) =28a(3) =111a(4) =435a(5) =1707a(6) =6723a(7) =26571a(8) =105315a(9) =418347a(10) =1664643a(11) =6632331a(12) =26450595a(13) =105566187a(14) =421556163a(15) =1684098891a(16) =6730018275a(17) =26900941227a(18) =107546369283a(19) =430013290251
External references
- oeis: A306545