Harvey Friedman (born September 23, 1948) is a mathematical logician who taught at the Ohio State University until his retirement in the summer of 2012.
Since 1997, Friedman has been continuing a series of posts to New York University's FOM (Foundations of Mathematics) mailing list which he calls the "numbered posts." They cover a wide range of topics in mathematical logic, and some of the research involves large numbers. For example, he discovered the block subsequence theorem, circle theorem, the TREE sequence and the subcubic graph numbers. His finite promise games exceeds even Loader's function.
Friedman is also a self-taught amateur pianist.