Which presidents were not masons?

As of 1/1/2010 only the following 15 Presidents are verified Masons - the rest are not:

George Washington

James Monroe

Andrew Jackson

James K. Polk

James Buchanan

Andrew Johnson

James Garfield

William McKinley

Theodore Roosevelt

William H. Taft

Warren G. Harding

Franklin D. Roosevelt

Harry S. Truman

Lyndon Johnson

Gerald Ford