- #1

danne89

- 180

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**distinct**factors of a number, say, 2520?

2520 = 2*2*2*3*3*5*7

So we've 8 different primes. The number of combinations of those is, according to me:

C(8,1)+C(8,2)+...+C(8,8)=155 (I think, calculated it by hand; but it isn't important)

Obviously those aren't distinct. (Pick the fist 2 and the second 2 = 4, but pick the second 2 and the third 2 also = 4.) :yuck: