Help with differential equation

Hi guys,

I'm building a snake robot that has 16 servo motors. ( 8 linear, 8 lateral and alternating)

Basically the programming side of it is fine but I need to evaluate a differential equation to show how the values are obtained for each servo.

The equation is attached. N corresponds to the servo (1-16, Odd being lateral and the even being linear) and t is the time interval. Offset is typically a value of approximately zero degrees (used to steer the robot) and theta is the frequency of the sine wave.

Can anybody help me with this? Im not very good with excel!

Thanks for looking