  We study numerically the magnetic susceptibility of the hierarchical model
with Ising spins ($\sigma =\pm 1$) above the critical temperature and for two
values of the epsilon parameter. The integrations are performed exactly, using
recursive methods which exploit the symmetries of the model. Lattices with up
to $2^18$ sites have been used. Surprisingly, the numerical data can be fitted
very well with a simple power law of the form $(1- \beta /\beta _c )^{- \gamma}
$for the {\it whole} temperature range. The numerical values for $\gamma $
agree within a few percent with the values calculated with a high-temperature
expansion but show significant discrepancies with the epsilon-expansion. We
would appreciate comments about these results.
