Article date: Mar 1963
Article title: A new paradox, and variations on it, about a man condemned to be hanged
Mathematical Games column? Y
Book: 5. The Unexpected Hanging and Other Mathematical Diversions
Chapter: 1. The Paradox of the Unexpected Hanging
This data confirmed? yes
Notes
Peter Rowlett (27 August 2022):
Peter Rowlett initial guess (Uncertain)
Peter Rowlett (29 October 2023):
I have seen this chapter and column side-by-side and they match.