What is the next equation?

Question

I need the answer to this equation. 3,-6,12,4,20,?

Answer 1

I assume you are trying to find the next number in the sequence. To do this, I used the TI-84 statistical functions and, doing a least squares fit, found a quartic equation that fits these data points with an r² value of 1.0 (perfect fit)

The equation is:

Using this equation, we can plug in x = 6 to get the 6th term which is 213