seasonal is an easy-to-use R-interface to X-13ARIMA-SEATS,
a seasonal adjustment software developed by the United
States Census Bureau. X-13ARIMA-SEATS combines and extends
the capabilities of the older X-12ARIMA (developed by the
Census Bureau) and the TRAMO-SEATS (developed by the Bank
of Spain) software packages.The best way to start is to have a look at the vignette:
vignette("seas")