133501

Appears in sequences

• a(n) = Sum_{k = 0..n} binomial(n,k)^3*binomial(n+k,k)^2.at n=4A014180
• a(n) is the number of labeled triangle-free simple graphs on n vertices.at n=6A213434
• Irregular triangle read by rows where T(n,k) is the number of labeled simple graphs with n vertices and exactly k triangles, 0 <= k <= binomial(n,3).at n=42A372170