Using all of the digits $1$ through $9$ and concatenating them freely to form decimal integers, different sets can be formed. Interestingly with the set $\{2,5,47,89,631\}$, all...
Using a combination of grey square tiles and oblong tiles chosen from: red tiles (measuring two units), green tiles (measuring three units), and blue tiles (measuring four...
Working from left-to-right if no digit is exceeded by the digit to its left it is called an increasing number; for example, $134468$. Similarly if no digit...
Working from left-to-right if no digit is exceeded by the digit to its left it is called an increasing number; for example, $134468$. Similarly if no digit...