Numbers in recreational mathematics

This page contains numbers appearing in recreational mathematics.
== List of numbers appearing in recreational mathematics ==
*The number 121 is the fourth largest undulating square number; this has been proved by David Moews.David Moews (1998) No more undulating squares
*125 is a Canada number.Canada numbersOEIS. A070308 "Canada perfect numbers": n such that the sum of digits^2 of n equals the sum of d|n, 1<d<n.
*The number 484 is the third largest undulating square number; this has been proved by David Moews.
*581 is a Canada number.
*The number 676 is the second largest undulating square number; this has been proved by David Moews.
*(728, 729) is the first pair of Smith brothers,Wolfram MathWorld. https://mathworld.wolfram.com/SmithBrothers.html i.e., consecutive Smith numbers.Wolfram MathWorld. Smith Number
*8,549 and 16,999 are the two largest known Canada numbers.
*The number 69,696 is the largest undulating square number; this has been proved by David Moews.
== Sources ==
Category:Numbers
Category:Lists
Category:Class 1
Category:Numbers with 3 digits
Category:Numbers with 4 to 6 digits