Problem C. 1350. (April 2016)
C. 1350. Define the sequence \(\displaystyle (a_n)\) as follows: \(\displaystyle a_1=1\), and \(\displaystyle a_{n+1}=a_n+4n\) for \(\displaystyle n>0\). Prove that each term of sequence \(\displaystyle (a_n)\) can be expressed as a sum of two consecutive square numbers.
(5 pont)
Deadline expired on 10 May 2016.
Statistics:
92 students sent a solution.  
5 points:  66 students. 
4 points:  11 students. 
3 points:  4 students. 
2 points:  5 students. 
1 point:  5 students. 
0 point:  1 student. 
