Amikoj who like maths: I'm trying to find the name of a math operation. Please help if interested!
It's similar to "choose"
4 choose 2 = 6
because there are six ways to choose 2 things from four. Similarly,
5 choose 2 = 10
There are ten ways.
But what if the five things are in a circle and we don't (re)count as new instances the ones that look the same when rotated?
5 ___ 2 = 2 (I'm pretty sure)
The 2 items can be either 1 and 4 apart or 2 and 3 apart.
I'm looking for the underlined operation.
5 ___ 3 = 2
If the items are ABCDE, where E is connected to A, the two configurations are 1. ABC (three together), 2. ABD (two, skip one, one). In the case of 5 items ACD is equivalent to 2 because CDA is two, skip one, one.For my purposes they must be equivalent by rotation only, not by flipping.
6 ___ 3 = 4
ABCDEF has ABC, ABD, ABE, and ACE. All others should be equivalent if I counted correctly.
What is this operation called? 🙏