Triangle read by rows: T(n,k) is the number of n-permutations whose fourth-shortest cycle has length exactly k; n >= 0, 0 <= k <= max(0,n-3).

A350274

Triangle read by rows: T(n,k) is the number of n-permutations whose fourth-shortest cycle has length exactly k; n >= 0, 0 <= k <= max(0,n-3).

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =23a(5) =1a(6) =109a(7) =1a(8) =10a(9) =619a(10) =16a(11) =45a(12) =40a(13) =4108a(14) =92a(15) =210a(16) =420a(17) =210a(18) =31240a(19) =771a(20) =1645a(21) =2800a(22) =2520a(23) =1344a(24) =268028a(25) =6883a(26) =17325a(27) =15960a(28) =26460a(29) =18144

External references