  Kastor and Traschen constructed totally anti-symmetric conserved currents
that are linear in the Riemann curvature in spacetimes admitting Killing-Yano
tensors. The construction does not refer to any field equations and is built on
the algebraic and differential symmetries of the Riemann tensor as well as on
the Killing-Yano equation. Here we give a systematic generalization of their
work and find divergence-free currents that are built from the powers of the
curvature tensor. A rank-4 divergence-free tensor that is constructed from the
powers of the curvature tensor plays a major role here and it comes from the
Lanczos-Lovelock theory.
