Section: 
A. Introduction

Dr Colin Rose
 
Comparison Table
 
Notes: 1. Armstrong numbers (Sloane A005188), also known as pluperfect digital invariants, are mdigit numbers n equal to the sum of the m^{th} powers of their digits. Here is a 3digit example: 407 = 4^{3} + 0^{3} + 7^{3} They are neither wild nor pretty because they require the use of the the power term m (the 3 in this example) over and above the digits of integer n (or, alternatively, the use of more than one copy of each digit of n) to achieve a solution. They are sometimes known as mnarcissistic numbers. However, the use of the term 'narcissistic' to describe them seems more confusing than it is helpful. 2. The subset of Friedman numbers that are ordered are pretty wild. Ordered Friedman numbers are known as 'nice' Friedman numbers (see Sloane A080035).
 