MathDB
IOQM 2021 P18

Source:

January 17, 2021

Problem Statement

If k=140(1+1k2+1(k+1)2)=a+bc\sum_{k=1}^{40} \left( \sqrt{1 + \frac{1}{k^{2}} + \frac{1}{(k + 1)^{2}}}\right) = a + \frac {b}{c} where a,b,cN,b<c,gcd(b,c)=1,a, b, c \in \mathbb{N}, b < c, gcd(b,c) =1 , then what is the value of a+b?a+ b ?