  The purpose of this note is to give an insertion scheme proof of the formula,
$$p_\mu = \sum_{\lambda\vdash k} \chi^\lambda(\mu)s_\lambda,\formula$$ where
$p_\mu$ is the power sum symmetric function, $s_\lambda$ is the Schur function
and $\chi^\lambda(\mu)$ is the irreducible character of the symmetric group
$S_k$ indexed by the partition $\lambda$ and evaluated at a permutation of
cycle type $\mu=(\mu_1,\ldots,\mu_\ell)$. The proof of this formula is by
direct application of the Robinson-Schensted-Knuth insertion scheme and a
recent formula of Roichman.
