266117 is a prime number.

arithmetic/digits/prime/square.difference New

New entry, edited from material collected for the archive and not yet in a released version.

Problem

266117 is a prime number.  Find two squares whose difference ends in
this prime number.

Show solution

a^2 - b^2 = (a-b)(a+b).  If 266117 is prime, a-b must be 1, so the only
solution 133059^2 - 133058^2 = 17704697481 - 17704431364.

-- Jonathan Dushoff <dushoff@gate.sinica.edu.tw>

[ Editor: this answer reads "ends in" as "is equal to"; the difference
is 266117 exactly. ]