def facp(n) :
  for i in xrange(2,n) :
    while n%i == 0 :
      n /= i
      yield i
    if i**2 > n : break
  if n!=1 : yield n

for n in xrange(3,99999) :
  p = list(facp(n/2))+list(facp(n+1)) if n%2==0 else list(facp(n))+list(facp((n+1)/2))
  c = reduce( lambda x,y: x*y, [p.count(i)+1 for i in set(p)] )
  if c > 500 : break
print n*(n+1)/2

1238961楼: Originally posted by huycwork at 2011-05-17 11:10:45
你又遍历！...