807404
[Commentary:
Third, fourth, and fifth powers of (20 + 4).
The binomial coefficients 3, 3 and 4, 6, 4 and 5, 10, 10, 5, appear amongst the numbers in the rightmost column.]
The binomial coefficients 3, 3 and 4, 6, 4 and 5, 10, 10, 5, appear amongst the numbers in the rightmost column.]