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/sci/ - Science & Math

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i'm sure this should be easy, but i was trying to figure out in how many ways can k men for k > 2 suck each other's dick if everyone's sucking a dick. i'm guessing it's something like (k-1)! but i can't count for shit
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>>9230316
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>>9230320
i don't have k friends. i could use a computer to figure it out for some numbers without having to suck dick anyway
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>>9230316
well think about what relation you want, and things you know about counting it.

if people can suck their own dicks, you are interested in arbitrary bijections from k-->k, and we know the size of this set is k! (first person can be assigned any of k people, second any of k-1 remaining, etc.). if not you are counting the size of the set of bijections k-->k with no fixed points. see if there is a systematic way to remove these from the original set.
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>>9230335
Would it be k!-(kC1)(k-1)!+(kC2)(k-2)!-(kC3)(k-3)!... using inclusion-exclusion?
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>>9230316
Well, there's just simple permutations of a single loop, then you have to add permutations of a loop of 2 and k-2, then 3 and k-3, etc, then permutations of 3 loops, etc, until you get to the degenerate (in more than one sense) case of everyone in 69 unless you have a threesome.
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>>9230316
If autofellatio is allowed, Suck(k+1)=(k+1)*Suck(k)
If autofellatio is not allowed, Suck(k+1)=(k+1)*Suck(k)-(-1)^k
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>>9230316
What if you allow the possibility of m of the k men being able to suck their own dick?
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>>9230316
it approaches n!/e if i remember correctly
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>>9230422
not counting them sucking their own dick
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>>9230316
Ouroboros : The fag that sucks his own dick which is fucking his ass.
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>>9230406
well that just means that you're allowed to have loops of size 1, rather than the minimum being size 2
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Reminds me of a puzzle I once contemplated:

Given a group of men and women, what's the smallest number you need to daisychain such that every possible oral sex combination is achieved. i.e Man sucking off a man while being sucked off by another man, man sucking off a man while being sucked off by woman, woman eating out a woman while sucking off a man, etc.?
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>men

why no make them cute traps with feminine penises?

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