ROSECODE 509
Higher order recursive sequence
Define a sequence as below: . Then , ,...Obviously all numbers in this sequence are rational.
For a prime and a fully reduced fraction , define to be the smallest positive for which . For example , because and is the smallest positive such number.
You are given , .
Find the sum of over all primes between 2000000000 and 2000100000.
Thanks to czp for the idea.
For a prime
You are given
Find the sum of
Thanks to czp for the idea.