Number of pairs of functions f, g from a size n set into itself satisfying f(f(g(x))) = g(g(f(x))).
A239776
Number of pairs of functions f, g from a size n set into itself satisfying f(f(g(x))) = g(g(f(x))).
Terms
- a(0) =1a(1) =1a(2) =12a(3) =189a(4) =5200a(5) =208945a(6) =11517936a(7) =828676933
External references
- oeis: A239776