Problem 615

[beco]

Congratulations to the first 100!

I've tried, but due to lots of not so much prime factors, I couldn't!

I'm specially amused by the time achieved by the Japanese flag user uwi. Just 10 minutes!

That got me thinking...

[Jochen_P]

Can someone confirm the 1000th number with at least 5 Prime Factors to be 9576 ?
thank you

[hk]

This simple program tells you the answer:

Code: Select all

def primefactorcnt(n):
    res=0
    f=2
    while n>1:
        while n%f==0:
            n/=f
            res+=1
        f+=1
    return res
cnt=0
for n in xrange(2,10000):
    k=primefactorcnt(n)
    if k>=5:
        cnt+=1
        if cnt==1000:
            print n
            break

[Jochen_P]

well, yeah, sure. Thanks
should've seen the ease of selftesting.

Now to find out where and why the easy to spot pattern from the example values breaks