154280

Appears in sequences

• a(n) = A016755(n) - A001845(n).at n=28A188050
• Irregular triangular array read by rows T(n,k) is the number of 2-colored labeled graphs that have exactly k edges, n >= 2, 0 <= k <= A033638(n).at n=44A201143
• a(n) = binomial(n,2)*(binomial(n-1,2) + 2).at n=28A352405