Intereting Posts

Algorithm to get the maximum size of n squares that fit into a rectangle with a given width and height
Proof by Contradiction, Circular Reasoning?
free software to create equations and export to various formats
Limit of the sequence of regular n-gons.
Distribution of sums of inverses of random variables uniformly distributed on
What is the value of $\int_C\dfrac{f(z)}{z-z_0}dz?$
Get the adjacency matrix of the dual of a 3-connected $k$-regular $G$ without pen and paper
Product of Permutations
Consider a right angled $\triangle PQR$ right angled at $P$ i.e ($\angle QPR=90°$) with side $PR=4$ and area$=6$.
The method of proving the equality of integrals by showing they agree within $\epsilon$, for an arbitrary $\epsilon>0$
Is there a problem when defining exponential with negative base?
Prove where exp: Skew($3\times 3$) $\rightarrow SO(3)$ is local homeomorphism
Does convergence in H1 imply pointwise convergence?
How to solve this operation research problem using dual simplex method?
Simplify $2^{(n-1)} + 2^{(n-2)} + … + 2 + 1$

I came across with a problem where I was required to examine primality of $n! +1$ (17! + 1 was the actual number).

Although Wilson’s Theorem could be manipulated for determining primality of $n! + 1$ when $n + 1$ is a prime and $n! – 1$ when $n + 2$ is a prime, it does not cover the specific example that I am dealing with. Is there any formula (or a more generalized formula that covers the whole problem space) for determining primality of $n! +1$ when $n + 1$ is not a prime?

- A contradiction or a wrong calculation? $3\lt\lim_{n\to\infty}log_n(p)\lt3$, $\forall n$ (sufficiently large) where $n^3\lt p\in\Bbb P\lt(n+1)^3$?
- What's known about the number of primes in the range $(n..2n)$?
- Help in understanding the proof of Mersenne Prime
- Problems about consecutive semiprimes
- Primes $p$ such that $2$ is a primitive root modulo $p$ , where $p=4\cdot k^2+1$?
- Find the five smallest positive integer $W$

- Explain Carmichael's Function To A Novice
- A prime number random walk
- Understanding a plot of composite numbers against the ordinal position of their prime factors
- Nature of the series $\sum\limits_{n}(g_n/p_n)^\alpha$ with $(p_n)$ primes and $(g_n)$ prime gaps
- Cyclic rearrangements of periods of the decimal expansions of certain rationals
- Proof concerning Mersenne primes
- Prime counting function; when is it true that $\pi(n) > \pi(2n) -\pi(n)$?
- $h+k=p-1$, $p$ prime. Prove $h!k! + (-1)^h \equiv 0 \pmod{p}$?

- Proof on cubic residues
- Proving $\displaystyle\lim_{h\to0}\frac{f(x+h)-2f(x)+f(x-h)}{h^2}=f''(x)$
- elementary proof that infinite primes quadratic residue modulo $p$
- Prove that $(G, \circ)$ is a group if $a\circ x = b$ and $x\circ a = b$ have unique solutions
- How to calculate $|f|_{0}$?
- 2 aliens walk on a line meeting probability.
- Show a Cubic Polynomial over $\Bbb C$ can be factored as a product of linear terms
- Functions satisfying $f(m+f(n)) = f(m) + n$
- Is the real number structure unique?
- Find the trajectories that follow drops of water on a given surface.
- Exploring 3-cycle points for quadratic iterations
- How to show $x_1,x_2, \dots ,x_n \geq 0 $ and $ x_1 + x_2 + \dots + x_n \leq \frac{1}{2} \implies (1-x_1)(1-x_2) \cdots (1-x_n) \geq \frac{1}{2}$
- Is a chain-complete lattice a complete lattice without the axiom of choice?
- The equation $a^3 + b^3 = c^2$ has solution $(a, b, c) = (2,2,4)$.
- Real Analysis, Folland Theorem 1.19 Borel Measures