From: utzoo!decvax!watmath!ghgonnet Newsgroups: net.math Title: numeros lindos Article-I.D.: watmath.2761 Posted: Sun Jun 20 22:27:19 1982 Received: Tue Jun 22 02:55:18 1982 Many years ago, we met a nutty, self-taught type who was searching for what he called "numeros lindos" (pretty numbers). These numbers have the property that when squared (or any power) the last digits coincide with the initial number. E.g. 109376 ** 2 = 11963109376. How many lindos are there with n digits? How to generate them? Is this problem known in the literature? (In base 10 this problem is not trivial, since 10 is not a prime) Gaston H. Gonnet Waterloo