Step 1: take a natural number N1 = 5, calculate the square of N1 plus 1 to get A1; step 2: calculate the sum of all numbers of A1 to get N2, calculate the square of N2 plus 1 to get A2 Three steps: calculate the sum of the numbers of A2 to get N3, and add 1 to the square of N3 to get A3

Step 1: take a natural number N1 = 5, calculate the square of N1 plus 1 to get A1; step 2: calculate the sum of all numbers of A1 to get N2, calculate the square of N2 plus 1 to get A2 Three steps: calculate the sum of the numbers of A2 to get N3, and add 1 to the square of N3 to get A3

n1=5,a1=26
n2=8,a2=65
n3=11,a3=122
n4=5,a4=26
..
In this cycle, the period is three
2008 divided by 3, more than 1
So, n2008 = 5
a2008=26