Number of connected graphs on n labeled nodes, each node being colored with one of 3 colors, such that no edge joins nodes of the same color.

A002028

Number of connected graphs on n labeled nodes, each node being colored with one of 3 colors, such that no edge joins nodes of the same color.

Terms

    a(0) =1a(1) =3a(2) =6a(3) =42a(4) =618a(5) =15990a(6) =668526a(7) =43558242a(8) =4373213298a(9) =677307561630

External references