If you use formula in C++, you don't need the long arithmetics. Use long double and you'll get AC.

i used long double,
2 4 6 29 -1000
but my answer is -6.00693e+208, is it correct or not?

you should turn off siencetific notation

My approach goes like this: lets choose a big random prime P > 10^16, and calculate F_(i+1)%P.