  We present Washington system colour-magnitude diagrams (CMDs) for 17
practically unstudied star clusters located in the bar as well as in the inner
disc and outer regions of the Large Magellanic Cloud (LMC). Cluster sizes were
estimated from star counts distributed throughout the entire observed fields.
Based on the best fits of theoretical isochrones to the cleaned $(C-T_1,T_1)$
CMDs, as well as on the $\delta T_1$ parameter and the standard giant branch
method, we derive ages and metallicities for the cluster sample. Four objects
are found to be intermediate-age clusters (1.8-2.5 Gyr), with [Fe/H] ranging
from -0.66 to -0.84. With the exception of SL263, a very young cluster ($\sim$
16 Myr), the remaining 12 objects are aged between 0.32 and 0.89 Gyr, with
their [Fe/H] values ranging from -0.19 to -0.50. We combined our results with
those for other 231 clusters studied in a similar way using the Washington
system. The resulting age-metallicity relationship shows a significant
dispersion in metallicities, whatever age is considered. Although there is a
clear tendency for the younger clusters to be more metal-rich than the
intermediate ones, we believe that none of the chemical evolution models
currently available in the literature reasonably well represents the recent
chemical enrichment processes in the LMC clusters. The present sample of 17
clusters is part of our ongoing project of generating a database of LMC
clusters homogeneously studied using the Washington photometric system and
applying the same analysis procedure
