a(n,k) equals (1/n!) multiplied by the count of permutations with cycle length k in all products u v u^-1 v^-1 over all permutations u and v of length n.
A191716
a(n,k) equals (1/n!) multiplied by the count of permutations with cycle length k in all products u v u^-1 v^-1 over all permutations u and v of length n.
Terms
- a(0) =1a(1) =0a(2) =2a(3) =3a(4) =0a(5) =3a(6) =0a(7) =19a(8) =0a(9) =5a(10) =40a(11) =0a(12) =73a(13) =0a(14) =7a(15) =0a(16) =492a(17) =0a(18) =217a(19) =0a(20) =11a(21) =1260a(22) =0a(23) =3225a(24) =0a(25) =540a(26) =0a(27) =15a(28) =0a(29) =24096
External references
- oeis: A191716