Exercise your brain: Brain Teaser

1.- What do the following numbers have in common?

3    7    10    11    12

 

 

2.- What is the next number in this series?

5   25   61   113   181   ...

 

 

 

The only vowel they contain, when written out fully, is the letter E


265. (The series consists of the sums of the squares of 1 and 2, 3 and 4, 5 and 6, etc