Number of ways to partition the (vertex) set {1,2,...,n} into any number of classes and then select some unordered pairs (edges) <a,b> such that a and b are in distinct classes of the partition.

A240936

Number of ways to partition the (vertex) set {1,2,...,n} into any number of classes and then select some unordered pairs (edges) <a,b> such that a and b are in distinct classes of the partition.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =21a(4) =337a(5) =11985a(6) =930241a(7) =155643329a(8) =55638770689

External references