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15 votes
0 answers
365 views

Do primes of the form $4k+1$ ever lead the greatest prime factor race?

Analogous to Chebyshev's race between primes, I examined the race between primes in the greatest prime factors, GPF, of natural numbers. Similar to the regular prime race, in the GPF race, the ...
Nilotpal Kanti Sinha's user avatar
7 votes
0 answers
274 views

Are there infinitely many zeroes of $\sum_{r = 1}^{n-1} \mu(r)\gcd(n,r) $?

Let $\mu(n)$ be the Möbius function and $S(x)$ be the number of positive integers $n \le x$ such that $$ \sum_{r = 1}^{n-1} \mu(r)\gcd(n,r) = 0 $$ My experimental data for $n \le 6 \times 10^5 $...
Nilotpal Kanti Sinha's user avatar
6 votes
0 answers
200 views

Empirical bounds on $\left|\frac{\zeta'(1+it)}{\zeta(1+it)}\right|$

It is reasonable to expect that $$\left|\frac{\zeta'(1+it)}{\zeta(1+it)}\right| < 2 \log \log t$$ for all $t\geq 4$ (say): a somewhat stronger bound is known for $t\geq 10^{165}$ or so (Theorem 5 ...
H A Helfgott's user avatar
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6 votes
0 answers
290 views

Effective bounds for Fermat's Last Theorem

Suppose $n>2$. By Fermat's Last Theorem, we know that $a^{n}+b^{n}=c^{n}$ has no non-trivial solutions. Can we quantify it more? More specifically, given $a,b,c,n\in\mathbb{N}$ with $n>2$ and $...
Gorav Jindal's user avatar
3 votes
0 answers
186 views

Factoring problem similar to $RSA$ structure that is possibly not $NP$ complete and not $coNP$ also?

Standard factoring problem $\Pi_1$ is 'Given integers $N$ and $M$ is there a factor $d\in[1,M]$ of $N$?'. This is in $NP$ since such a factor is the witness and in $coNP$ since one can check all the ...
Turbo's user avatar
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2 votes
0 answers
107 views

Record for determining complete list of imaginary quadratic fields with small class number

In 2003, Mark Watkins (Class numbers of imaginary quadratic fields) determined all imaginary quadratic fields having class number at most 100. Has this list been improved? That is, what is the largest ...
Stanley Yao Xiao's user avatar
2 votes
0 answers
146 views

Reference for accelerated sum to compute the Meissel-Mertens constant

The Meissel-Mertens constant $$ B_1 = \lim_{n \to \infty} \left(\sum_{p \leq n} \frac{1}{p} - \log\log n\right) $$ has the series representation $$ \begin{equation} \tag{1} B_1 = \gamma + \sum_{n=2}^{...
Greg Hurst's user avatar
2 votes
0 answers
205 views

Sum of all primes below $n$ without listing all primes below $n$

Asymptotically there is around $\frac{n}{\ln n}$ primes below a given integer $n$. Thus $\frac{n}{\ln n}$ is a lower bound for the time complexity of any algorithm that at some point finds each prime ...
vlben's user avatar
  • 21
2 votes
0 answers
99 views

A problem in modular roots

We have three mutually coprime integers $r,t,M$ where $M\asymp K^{\frac12-2\epsilon}$ and $r,t\asymp K^{\frac14+\epsilon}$ holds with some fixed $\epsilon>0$ and $K>0$ is a large parameter. ...
Turbo's user avatar
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2 votes
0 answers
78 views

Accelerating convergence of a product by multiplying by zeta values: history?

Let $R(s_1,\dotsc,s_n) = \prod_p r(p^{-s_1},\dotsc,p^{-s_n})$, where $r$ is a rational function on $n$ variables. Say we want to compute the value of $R(s_1,\dotsc,s_n)$ for some choice of $s_1,\dotsc,...
Nell's user avatar
  • 545
2 votes
0 answers
127 views

Coppersmith's method to quadrivariate degree $2$ polynomials that behave as bivariate?

We have a polynomial $f(x_1,x_2,x_3,x_4)\in\mathbb Z[x_1,x_2,x_3,x_4]$ where the only monomials are either from set $$\{x_1,x_1x_2,x_2,x_3,x_3x_4,x_4\}$$ and we seek solutions $(x_1,x_2,x_3,x_4)\in\...
Turbo's user avatar
  • 13.9k
2 votes
0 answers
132 views

Quick computation of a certain exponential sum

Is there a quick way to compute (somewhat accurately) for large $X$, the following exponential sum, where $\Lambda$ is the von Mangoldt function? $$\int_0^1 \bigg|\sum_{n\le X} \Lambda(n)e(n\alpha)\...
Mayank Pandey's user avatar
1 vote
0 answers
84 views

How common are semiprimes with equally bitsized factors among semiprimes with equal bitsize?

I am curious about the following after having looked at the paper "Almost primes in almost all short intervals", theorem 3 says: Almost all intervals $[x, x + \log^{3.51}{(x)}]$ with $x ≤ X$...
factorn's user avatar
  • 11
1 vote
0 answers
96 views

Smooth number pairs satisfying a congruence

Let $\mathcal P=\{p_1,\dots,p_{2t}\}$ be $2t$ primes between $2^\ell$ and $2^{\ell+1}$ and fix an exponent bound $a\in\mathbb Z_{\geq2}$. Fix $N\in\mathbb N$ whose prime factors $p$ satisfy $p>2^{\...
Turbo's user avatar
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