In this sequence there are actually two sequences. 1 sequence for the numerators and one sequence for the denominators. The following transformation applies to the sequence for the denominators : -7

This creates the following sequence: [1, -6, -13, -20, -27, -34, -41]

The following transformation applies to the sequence for the numerators: -10

This creates the following sequence: [1, -9, -19, -29, -39, -49, -59]

Take a good look at how to rewrite the fractions in the series to recognize the pattern.

For example, 2/3 can be rewritten as -6/-9