Consider the family of multigraphs enriched by the species of quaternary sets. Sequence gives number of those multigraphs with 4n edges.

A099684

Consider the family of multigraphs enriched by the species of quaternary sets. Sequence gives number of those multigraphs with 4n edges.

Terms

    a(0) =1a(1) =1a(2) =71a(3) =52966a(4) =188004311

External references