find the number of ordered triples $(x,y,z)$
4943
If $p,q,r$ are all primes,and $p|qr-1$,$q|pr-1$ and $r|pq-1$,find all possible values of $pqr$.
27273
Count the number of topological sorts for poset (A|)?
8434
Order of $\mathbb{Z}[i]/(1+i)$
78422
Calculate the number $o(\mathbb{R})$ of open subsets of the real line.
142038
Finding the number of elements of order two in the symmetric group $S_4$
52348
Counting the number of surjections.
97908
Finding the no. of possible matrices given the order and limited no. of entries
83496
Math contest integer triplet problem: $x + y + z + xy + yz + xz = xyz − 1$
94697
Grouping the first two elements in a list of ordered triples
44013
How many trees over ${1,2,3,...n}$ with conditions
29232
Find total number of relations that are equivalence as well as partial order set
26343
Number of certain (0,1)-matrices, Stanley's Enumerative Combinatorics
111954
Computing the cardinality of a combinatorial set
114996
$x+y+z=n$. Finding the number of solutions.
114752
Number of permutations of a specific cycle decomposition
31318
Cardinality of cartesian square
30172
Why is the order of $\mathbb{Z}[i]/\langle 3+i\rangle$ equal to 10?