Number of permutations when $1$ does not immediately precede $2$ ...
41008
how many permutations of {1,2,...,9}
98313
Number of possible permutations of n1 1's, n2 2's, n3 3's, n4 4's such that no two adjacent elements are same?
144821
Number of ordered pairs of subsets
128834
Proving the number of even and odd permutations of a subgroup $H<S_{n}$ are equal, provided $H$ is not contained in $A_{n}$
29678
Circular Permutation
34452
In how many ways can you choose $k$ numbers out of $\{1,2,3,\dots,n\}$ so none of them is consecutive?
108747
A simple permutation question - discrete math
37331
Prove that every set with more than one element has a permutation without fixed points
20221
Combinatorics - Removing Double Counted Cases
120744
How many $n\times m$ binary matrices are there, up to row and column permutations?
24212
proving how many permutations exist.
133848
Probability that 2 appears at an earlier position than any other even number in a permutation of 1-20
96585
Sums and permutation
48838
Proving the number of $n$ length binary strings with no consecutive $1's$ $b_n$ is equal to $b_{n-1} + b_{n-2}$
83837
Odd/Even Permutations
73323
Permutations when some objects are alike
131863
Permutation question on alphabets