Number of ordered pairs of cycles over all n-permutations having two cycles.
A052517
Number of ordered pairs of cycles over all n-permutations having two cycles.
Terms
- a(0) =0a(1) =0a(2) =2a(3) =6a(4) =22a(5) =100a(6) =548a(7) =3528a(8) =26136a(9) =219168a(10) =2053152a(11) =21257280a(12) =241087680a(13) =2972885760a(14) =39605518080a(15) =566931294720
External references
- oeis: A052517