Did any us president choose not to run for a 2nd term?

Lyndon Johnson Harry Truman Polk, Buchanan, Hayes, and Coolidge. Others have sought a second term, but either not been renominated - Tyler, Fillmore, Pierce, A Johnson, Arthur, L B Johnson - or else defeated in election - J Adams, JQ Adams, Van Buren, Harrison, Taft, Hoover, Ford, GHW Bush.