Number of pairs (f,g) of commuting maps {0,..,n-1}->{0,..,n-1} with 0 <= f(k), g(k) <= k.

A244524

Number of pairs (f,g) of commuting maps {0,..,n-1}->{0,..,n-1} with 0 <= f(k), g(k) <= k.

Terms

    a(0) =1a(1) =1a(2) =4a(3) =26a(4) =236a(5) =2780a(6) =40642a(7) =715836a(8) =14873174a(9) =358866952a(10) =9934283924a(11) =312461402424

External references