Arun Kumar
Last Activity: 10 Years ago
if we see
[sqrt(1)]=1
[sqrt(2)]=1
in fact for
1 its 1*(2^2-1^2)
for 2 2*(3^2-2^2)
similarly [root(2115)]=45
so sigma n((n+1)^2-n^2) from 1 to 44
then we take t=45*(2115-2045+1)
(2n+1(n+1)(n)/3+(n+1)(n)/2 put n=44 then add with t
get the answer