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Dan Brumleve
  • Member for 11 years, 11 months
  • Last seen more than 3 years ago
247 votes
9 answers
83k views

What is the importance of the Collatz conjecture?

36 votes
1 answer
859 views

Uses of "Collatz induction"?

25 votes
3 answers
4k views

What is the simplest way to prove that the logarithm of any prime is irrational?

24 votes
2 answers
512 views

Is there a polynomial such that $F(p)$ is always divisible by a prime greater than $p$?

23 votes
1 answer
915 views

How to prove there are an infinite number of squarefree numbers of the form $2^p-1$?

22 votes
3 answers
2k views

What are some examples of theories stronger than Presburger Arithmetic but weaker than Peano Arithmetic?

21 votes
0 answers
458 views

Does the sum of reciprocals of all prime-prefix-free numbers converge?

20 votes
1 answer
738 views

Short intervals with all numbers having the same number of prime factors

19 votes
2 answers
1k views

How to prove that $p-1$ is squarefree infinitely often?

17 votes
3 answers
5k views

What does "only" mean?

14 votes
4 answers
1k views

Can multiplication be defined in terms of divisibility?

13 votes
1 answer
466 views

Is there any infinite set of primes for which membership can be decided quickly?

11 votes
0 answers
359 views

Does Chaitin's constant have infinitely many prime prefixes?

11 votes
1 answer
308 views

Is $\sum_{n \ge 1}{\frac{p_n}{n!}}$ irrational?

11 votes
1 answer
359 views

Does there exist a computable number that is normal in all bases?

10 votes
4 answers
2k views

How to determine in polynomial time if a number is a product of two consecutive primes?

10 votes
2 answers
286 views

Is there any number greater than 8 of the form $2^{2k+1}$ which is the sum of a prime and a safe prime?

10 votes
2 answers
591 views

Is there any toy for learning algebraic manipulation of fractions?

9 votes
1 answer
645 views

Is there a binary spigot algorithm for log(23) or log(89)?

9 votes
2 answers
479 views

How to show the existence of an infinite set of independent undecidable sentences?

9 votes
3 answers
1k views

Defining addition of supernatural numbers?

8 votes
1 answer
246 views

What is the most parsimonious model of natural number computation?

8 votes
1 answer
121 views

How to prove that $5$ unit hypercubes cannot be positioned to cover a unit hypersphere?

7 votes
4 answers
320 views

Computing the first $n$ values of the Liouville function in linear time

7 votes
1 answer
461 views

Can a Pratt certificate for a prime be found in polynomial time?

7 votes
1 answer
1k views

Is there a simple way to prove Bertrand's postulate from the prime number theorem?

6 votes
2 answers
819 views

Is there a log-space algorithm for divisibility?

6 votes
3 answers
867 views

Testing graph isomorphism with powers of the adjacency matrix

6 votes
2 answers
821 views

Why is $\zeta(2) = \frac{\pi^2}{6}$ almost equal to $\sqrt{e}$? [closed]

6 votes
4 answers
632 views

Mental card game