  We propose exact expressions for the conformal anomaly and for three critical
exponents of the tricritical O(n) loop model as a function of n in the range
$-2 \leq n \leq 3/2$. These findings are based on an analogy with known
relations between Potts and O(n) models, and on an exact solution of a
'tri-tricritical' Potts model described in the literature. We verify the exact
expressions for the tricritical O(n) model by means of a finite-size scaling
analysis based on numerical transfer-matrix calculations.
