How do you do arithmetic sequences?

Answer 1

The answer will depend on what you mean by DO. An arithmetic sequence depends on two numbers: the seed, a, and the difference, d.

The first number in the sequence is the seed and each number is obtained from the previous one by adding the difference.

So U1 = a

U2 = a + d

U3 = U2 + d = a + d + d = a + 2d

U4 = U3 + d = a + 2d + d = a + 3d

and so on.

In general, Un = a + (n - 1)*d