1. The Original Gray Code
Herbert S. Wilf · Society for Industrial and Applied Mathematics eBooks · 1989
United States patent number 2,632,058, granted March 17, 1953 after having been applied for on November 13, 1947, to “Frank Gray, East Orange, N.J., assignor to Bell Telephone Laboratories, Incorporated, New York, N.Y., a corporation of New York” was for “pulse code communication” and it provided