Posted here are some comments/questions by our readers and ensuing conversations with them, related to mathematics/numbers.
Conversation with Bhaskar, who is a graduate from IIT (Kharagpur) (click to view)
Thanks to Bhaskar for initiating this conversation, that led to some detailed discussion on coprimes.
Bhaskar also shared with us the formula for sum of all coprimes, which is
Sum of all coprimes to n, which are less than n = n * phi(n) / 2.
The formula is very similar to sum of consecutive positive integers, n(n+1)/2.