How do I find a function in this sequence: -4, -7, -9, -10, -10, -9, -7, -4, 0, 5, 11, 18?

or:How do I find a function in this sequence: -4, -7, -9, -10, -10, -9, -7, -4, 0, 5, 11, 18?

or:How do I find a function in this sequence: -4, -7, -9, -10, -10, -9, -7, -4, 0, 5, 11, 18?

Tags:sequence,