Number of T_0-tricoverings of an n-set.

A060070

Number of T_0-tricoverings of an n-set.

Terms

    a(0) =1a(1) =0a(2) =0a(3) =5a(4) =175a(5) =9426a(6) =751365a(7) =84012191a(8) =12644839585

External references