Divisor Sums Problem 608
Let D(m,n)=∑d|mk=1nσ0(kd) where d runs through all divisors of m and σ0(n) is the number of divisors of n . You are given D(3!,102 )=3398 and D(4!,106 )=268882292 . Find D(200!,1012 ) mod (109 +7) .
测试程序

function D(m,n)
 function q(n)
 c=Int64(0)
 for i in 1:n
  if n%i==0 c+=1 end
 end
 c
 end
d=s=Int64(0)
for d in 1:m
if m%d==0
 for k=1:n
  s+=q(k*d)
 end
end
end
s
end

k*d有很多重复,如果能统计个数一次乘以个数,能省很多