Representative sample of the observable region of inflaton potentials allowed at the 95% CL, inferred from H(ϕ) when that function is Taylor-expanded at order n = 2, 3, and 4 in the observable region, making no assumption about the end of inflation, and using Planck TT,TE,EE+lowE+lensing+BK15. In natural units (where ). The scales are the same as in PCI15. Note that there is another branch of solutions symmetric under (ϕ − ϕ_*)→ − (ϕ − ϕ_*).