Consider the family of multigraphs enriched by the species of ternary sets. Sequence gives number of those multigraphs with 3n edges.

A099680

Consider the family of multigraphs enriched by the species of ternary sets. Sequence gives number of those multigraphs with 3n edges.

Terms

    a(0) =1a(1) =1a(2) =21a(3) =2689a(4) =1162525a(5) =1213162861

External references