I'm aware difference tables can be used to find the final term in the sequence - it's what I did to find the answer. I was using differential equations to find

I'm aware difference tables can be used to find the final term in the sequence - it's what I did to find the answer. I was using differential equations to find the equation that describes the sequence and I was wondering why the constant that you get when you integrate a function isn't actually a constant after the second integration.