- C415+C515+C615C_{15}^{4}+C_{15}^{5}+C_{15}^{6}
- C415⋅C511.C66C_{15}^{4} \cdot C_{11}^{5} . C_{6}^{6}
- A415⋅A511⋅A66A_{15}^{4} \cdot A_{11}^{5} \cdot A_{6}^{6}
- C415+C511+C66C_{15}^{4}+C_{11}^{5}+C_{6}^{6}