How come phi(2) has 2 values ? In the chain it is 1 and in the corresponding set of phi() values it is 2. And one more thing phi() is number of 'y' whoes gcd with 'x' is 1, so in the range of 1 to 900 there are 154 prime numbers, excluding 2,3 and 5 we have 151 prime numbers whose gcd with 900 will give 1 but the value given in corresponding set is 9. How ? Plz help.

Can somebody explain how S(3,2) is obtained in the explanation?

can any one display the code for this program

I can't understand how to generate the sequence.pls help me

yall guys need help???????????????????