The Number of different $n \times n$ Skew-symmetric matrices with each element being equal to either $0$ or $1$ or $-1$
97908
Finding the no. of possible matrices given the order and limited no. of entries
134440
An unexpected application of non-trivial combinatorics
83061
Generating the symmetric group $S_n$
107964
Simple combinatorics problem.
63260
Matrices whose Linear Combinations are All Singular
56828
A combinatorial proof that the alternating sum of binomial coefficients is zero
30003
Proving that Order for N is Anti-symmetric
57221
counting the number of elements in a conjugacy class of $S_n$
52564
$m\times n$ matrix with an even number of 1s in each row and column
47012
When a 0-1-matrix with exactly two 1’s on each column and on each row is non-degenerated? [1]
52040
"Inverse" of an $n\times k$ matrix.
36064
How many $3 \times 3$ integer matrices are orthogonal?
24212
proving how many permutations exist.
69833
Number of elements not equal to their inverses is even number
15202
the root of $N$th transpose matrix
96680
Generators of symmetric group $S_n$
58103
number of permutations in which no two consecutive numbers are adjacent