A positive number \(n\) is called a *coconut* if the logarithm of \(n\) to the base 10 is in the interval \([2,3) \).

Moreover, a natural number \(n\) is called *crunchy* if it suffices the following condition
\[\displaystyle \text{SOD}(3+n)=\dfrac{\text{SOD}(n)}{3}\]

,where \(\displaystyle \text{SOD}(n)\) is an operator which tells the sum of digits of the number \(\displaystyle n\).

What is the sum of all numbers that are both *crunchy* and *coconuts'*?

×

Problem Loading...

Note Loading...

Set Loading...