Taking the span in a polynomial ring

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I was trying to make a vector subspace of linear polynomials on the finite field of size 2 by taking

R.<X>=PolynomialRing(GF(2))
span([X^(2^j) for j in range(3)], GF(2))

But I get an error ending by :

ValueError: The elements of gens (= [X, X^2, X^4]) must be defined over base_ring (= Finite Field of size 2) or its field of fractions.

How do I fix this ?