  A fundamental problem in the representation theory of the symmetric group,
Sn, is to describe the coefficients in the decomposition of a tensor product of
two simple representations. These coefficients are known in the literature as
the Kronecker coefficients. The Littlewood--Richardson coefficients appear as
an important subfamily of the wider class of stable Kronecker coefficients.
This subfamily of coefficients can be calculated using a tableaux counting
algorithm known as the Littlewood--Richardson rule. This paper generalises one
half of this rule (the "co-Pieri" rule) to the the wider family of stable
Kronecker coefficients.
