Number of forests (sets) of rooted labeled trees on {1,2,...,n} such that the node with label 1 is in the same rooted tree as the node with label 2.
A221864
Number of forests (sets) of rooted labeled trees on {1,2,...,n} such that the node with label 1 is in the same rooted tree as the node with label 2.
Terms
- a(0) =0a(1) =0a(2) =2a(3) =11a(4) =88a(5) =930a(6) =12254a(7) =193736a(8) =3576564a(9) =75552560a(10) =1797906490a(11) =47601571968
External references
- oeis: A221864