What is the largest number k < 100,000 such that k has an odd number of factors?
9092
What is special about square numbers here?
134440
An unexpected application of non-trivial combinatorics
104010
The number of partitions of $n$ into distinct parts equals the number of partitions of $n$ into odd parts
11967
number of subsets of even and odd
75723
Odd Binomial Coefficients?
134066
Total number of factors of a number
144571
A conjecture including binomial coefficients
65757
Prove that $n! + k$ is a composite number
149509
What method would you go through to find an $n$ such that $\phi(n)=100$?
146439
Is every sufficiently large positive integer of the form $ab + ac + bc + 1$?
142477
Closed-form expression for the number of $k$-permutations of length $n$. Duplicates allowed!
16830
What is the most efficient way of finding all the factors of a number in Python?
2900
How many $3$-subsets of $\{1,2,\ldots,10\}$ contain at least one even and one odd integer?
57944
Euler's Formula application for distinct odd primes with gcd 1
156242
As many even numbers as natural numbers.
117761
When is $\binom{n}{k}$ divisible by $n$?
29084
Largest integer that can't be represented as a non-negative linear combination of $m, n = mn - m - n$? Why?