Fifty years of paintings filled the entire set of lower galleries at the Arvada Center for the Arts and Humanities this past fall when the epic Frank Sampson Retrospective was installed there. Throughout his career, Sampson was interested in figural abstraction, a taste that has come and gone and come back again during the intervening half-century since he first started doing them. Rudi Cerri, a former curator and exhibition designer at the Arvada Center, ably put together this spectacular and edifying exhibit, completely outdoing himself with this, his swan song.