near x = 3
> f:= x -> x^2+4*x-3;
> L:=[n, 2^(-n), (f(3+2^(-n))-f(3))/2^(-n), (f(3-2^(-n))-f(3))/(-2^(-n)), (f(3+2^(-n))-f(3-2^(-n)))/(2*2^(-n))];
> for n from 0 to 10 do print(evalf(L)); od;