  We present an analysis of ~5 years of Lick Observatory radial velocity
measurements targeting a uniform sample of 31 intermediate-mass subgiants (1.5
< M*/Msun < 2.0) with the goal of measuring the occurrence rate of Jovian
planets around (evolved) A-type stars and comparing the distributions of their
orbital and physical characteristics to those of planets around Sun-like stars.
We provide updated orbital solutions incorporating new radial velocity
measurements for five known planet-hosting stars in our sample; uncertainties
in the fitted parameters are assessed using a Markov Chain Monte Carlo method.
The frequency of Jovian planets interior to 3 AU is 26 (+9,-8)%, which is
significantly higher than the ~5-10% frequency observed around solar-mass
stars. The median detection threshold for our sample includes minimum masses
down to {0.2, 0.3, 0.5, 0.6, 1.3} MJup within {0.1, 0.3, 0.6, 1.0, 3.0} AU. To
compare the properties of planets around intermediate-mass stars to those
around solar-mass stars we synthesize a population of planets based on the
parametric relationship dN ~ M^{alpha}P^{beta} dlnM dlnP, the observed planet
frequency, and the detection limits we derived. We find that the values of
alpha and beta for planets around solar-type stars from Cumming et al. fail to
reproduce the observed properties of planets in our sample at the 4 sigma
level, even when accounting for the different planet occurrence rates. Thus,
the properties of planets around A stars are markedly different than those
around Sun-like stars, suggesting that only a small (~ 50%) increase in stellar
mass has a large influence on the formation and orbital evolution of planets.
