Hypersurfaces of type M23 in E24 with proper mean curvature vector

We show that if the mean curvature vector field of a hypersurface M23 in E24 satisfies the equation ΔH→=αH→ (αα a constant) then M23 has constant mean curvature. This equation is a natural generalization of the biharmonic submanifold equation ΔH→=0→.