How many ways to select $r$ items from $n$ items, without selecting any two consecutive items?
37051
Choosing numbers without consecutive numbers.
136037
${n\choose 2} - {k\choose 2} = {n-k\choose 2} +k(n-k)$ Marked box or unmarked box
5208
Which is faster/best? SELECT * or SELECT column1, colum2, column3, etc
102427
Skipping every even numbered item in the enumerate environment
60419
Randomly selecting elements without repetition
146098
Number of nonempty subsets of a set with $n$ elements
8173
Number of ways to choose $n$ balls from $3n$ balls, distinguishable/indistinguishable.
13722
how to get all possible combination of items from 2-dimensional list in python?
24146
Number of ways to partition a rectangle into n sub-rectangles
826
What is the number of ways to select ten distinct letters from the alphabet $\{a, b, c, \ldots, z\}$, if no two consecutive letters can be selected?
102136
How many subsets contain no consecutive elements?
45074
Combinatorics: Selecting objects arranged in a circle
96086
Double Factorial: Number of possibilities to partition a set of $2n$ items into $n$ pairs
108563
Detecting consecutive integers in a list
75392
How can I use Pick to select items in one list when a value in a corresponding list is $\leq$ some value?
45413
How can I get every nth item from a List?
115314
How do you efficiently return all of a List but one element?