  We explore the possibility of observing the anti-charmed pentaquark state
from the $\Theta_c \bar{n} \pi^+$ decay of $B$ meson produced at $B$-factory
experiments. We first show that the observed branching ratio of the $B^+$ to $
\Lambda^-_c p \pi^+$, as well as its open histograms, can be remarkably well
explained by assuming that the decay proceeds first through the $\pi^+
\bar{D}^0$ (or $\bar{D}^{*0}$) decay, whose branching ratios are known, and
then through the subsequent decay of the virtual $\bar{D}^0$ or $\bar{D}^{*0}$
mesons to $\Lambda_c^- p$, whose strength are calculated using previously fit
hadronic parameters. We then note that the $\Theta_c$ can be similarly produced
when the virtual $\bar{D}^0$ or $\bar{D}^{*0}$ decay into an anti-nucleon and a
$\Theta_c$. Combining the present theoretical estimates for the ratio $g_{D N
\Lambda_c} / g_{D N \Theta_c} \sim 13 $ and $g_{D^* N \Theta_c} \sim {1/3} g_{D
N \Theta_c}$, we find that the anti-charmed pentaquark $\Theta_c$, which was
predicted to be bound by several model calculations, can be produced via $B^+
\to \Theta_c \bar{n} \pi^+$, and be observed from the $B$-factory experiments
through the weak decay of $\Theta_c \to p K^+ \pi^- \pi^- $.
