180580

Appears in sequences

• Number of (w,x,y,z) with all terms in {1,...,n} and |w-x|>=|x-y|+|y-z|.at n=30A212574
• a(n)/A002939(n+1) is the Kirchhoff index of the join of the disjoint union of two complete graphs on n vertices with the empty graph on n+1 vertices.at n=21A338109