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Couldn't really understand the problem - Batselot - Dec-13-2018
Hi there everyone,this might be a dumb question to ask.But for this euler question I didn't know where to begin what the question meant,basically I couldn't understand where all those numbers came from.I would like to hear some basic explanation of the problem then I think I can move forward with this subject.
2-Friendly
Problem 643
Two positive integers a and b are 2-friendly when gcd(a,b)=2t,t>0. For example, 24 and 40 are 2-friendly because gcd(24,40)=8=23 while 24 and 36 are not because gcd(24,36)=12=22⋅3 not a power of 2.
Let f(n) be the number of pairs, (p,q), of positive integers with 1≤p<q≤n such that p and q are 2-friendly. You are given f(102)=1031 and f(106)=321418433 modulo 1000000007.
Find f(1011) modulo 1000000007.
RE: Couldn't really understand the problem - Gribouillis - Dec-13-2018
It simply means that the remainder of
f(10**6) divided by 1000000007 is 321418433. The question is to find the remainder of f(10**11) divided by 1000000007.