write a rescursive formula for an, the nth term of the sequence 1,-6,-13,-20 a1= an=

The recursive formula for an, the nth term of the sequence, can be represented as:

an = an-1 - 7

Here, a1 = 1, and an represents the value of the nth term in the sequence.

To write a recursive formula for the nth term (an) of the sequence 1, -6, -13, -20, we need to define how each term relates to the previous term.

We can see that the difference between consecutive terms increases by 7 each time: -6 - 1 = -7, -13 - (-6) = -7, -20 - (-13) = -7.

Therefore, the recursive formula for the sequence is:

a1 = 1 (the first term)
an = an-1 - 7, for n > 1 (every term thereafter is obtained by subtracting 7 from the previous term)