Joseph Madachy (March 16, 1927 – March 27, 2014) was a research chemist, technical editor and renowned recreational mathematician. He was the lead editor of Journal of Recreational Mathematics for nearly 30 years and then served as editor emeritus. Previously he was owner, publisher and editor of the predecessor Recreational Mathematics Magazine which ran during 1961–1964 with over 5000 subscribers.

In recreational mathematics he made numerous original contributions, was a major proponent and supporter for decades. Greenwood Press asked him to restart his journal in 1967, and for almost 30 years he was editor for the Journal of Recreational Mathematics which was published by Baywood Publishing from 1973. He authored the books Mathematics on Vacation, Madachy's Mathematical Recreations and Mathematical Diversions, and served as the literary agent for Dmitri Borgmann's Language on Vacation. Longtime colleagues and co-authors include Martin Gardner, Harry L. Nelson, and Isaac Asimov, and Solomon Golomb (with pentominos).
He worked with prime numbers, pentominos, amicable numbers and developed mathematical concepts used in applications such as cyber security with cryptarithmetic. He made contributions to Narcissistic numbers and Fibonacci series devising puzzles using Fibonacci numbers. His work in recreational mathematics covered other diverse areas from chess to magic squares to calculator art.

Fictional references:
Madachy is mentioned in the popular Jack Reacher novel series in the book Never Go Back regarding narcissistic numbers in the plot: "Such numbers had been much discussed by a guy called Joseph Madachy, who once upon a time had been the owner, publisher, and editor of a magazine called Journal of Recreational Mathematics."

Source: wikipedia.org