Triangular array read by rows. T(n,k) is the number of n-permutations with k cycles of length one or k cycles of length two, n>=0,0<=k<=n.
A237928
Triangular array read by rows. T(n,k) is the number of n-permutations with k cycles of length one or k cycles of length two, n>=0,0<=k<=n.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =1a(5) =1a(6) =3a(7) =3a(8) =0a(9) =1a(10) =18a(11) =14a(12) =9a(13) =0a(14) =1a(15) =95a(16) =75a(17) =35a(18) =10a(19) =0a(20) =1a(21) =540a(22) =369a(23) =135a(24) =55a(25) =15a(26) =0a(27) =1a(28) =3759a(29) =2800
External references
- oeis: A237928