The nth term of a sequence is given by the formula n^3 + 11n . Find the first four terms of the sequence given by this formula and the first term of the sequence which is bigger than one million. Prove that all terms of the sequence are divisible by 6.
Age 14 to 16 Short Challenge Level:
The sum of the three numbers x, y and z is 3x, so y + z = 2x.
So the mean of y and z is the same as the mean of 2x.
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