why division_polynomial results different with WIKI defines

edit

E = EllipticCurve(QQ,[0,0,1,-1,1]);E;E.short_weierstrass_model();E.division_polynomial(1);E.division_polynomial(2);E.division_polynomial(3);E.division_polynomial(4)


Elliptic Curve defined by y^2 + y = x^3 - x + 1 over Rational Field

Elliptic Curve defined by y^2 = x^3 - 16x + 80 over Rational Field 1 4x^3 - 4x + 5 3x^4 - 6x^2 + 15x - 1 8x^9 - 48x^7 + 210x^6 - 210x^4 + 198x^3 - 90x^2 + 142*x - 115

division_polynomial,2th=2y=2(x^3 - 16*x + 80)? from wiki http://en.wikipedia.org/wiki/Division...