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Dan Brumleve
  • Member for 12 years
  • Last seen more than 3 years ago
612 votes
6 answers
83k views

Why can you turn clothing right-side-out?

  • 6,123
257 votes
40 answers
30k views

Fun but serious mathematics books to gift advanced undergraduates.

162 votes
1 answer
7k views

What properties of busy beaver numbers are computable?

137 votes
6 answers
8k views

Why does mathematical convention deal so ineptly with multisets?

  • 62.7k
82 votes
1 answer
7k views

Direct proof that $\pi$ is not constructible

  • 209k
79 votes
3 answers
5k views

Mathematicians shocked(?) to find pattern in prime numbers

68 votes
10 answers
9k views

Is memory unimportant in doing mathematics?

65 votes
2 answers
4k views

When is an infinite product of natural numbers regularizable?

  • 1,009
41 votes
4 answers
3k views

Rain droplets falling on a table

38 votes
4 answers
3k views

Why is it considered unlikely that there could be a contradiction in ZF/ZFC?

35 votes
12 answers
8k views

Is this a valid proof that there are infinitely many natural numbers?

  • 439
33 votes
2 answers
762 views

Placing the integers $\{1,2,\ldots,n\}$ on a circle ( for $n>1$) in some special order

32 votes
3 answers
3k views

Proof of recursive formula for "fusible numbers"

  • 15k
32 votes
1 answer
964 views

Are sines of primes dense in $[-1,1]?$

28 votes
1 answer
1k views

FO-definability of the integers in (Q, +, <)

28 votes
1 answer
649 views

Power towers: to infinity and all the way back

  • 1,034
25 votes
1 answer
6k views

A proof of Wolstenholme's theorem

  • 217k
21 votes
2 answers
400 views

A strangely connected subset of $\Bbb R^2$

  • 62.7k
21 votes
2 answers
7k views

What's the difference between hyperreal and surreal numbers?

20 votes
1 answer
738 views

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

  • 17.4k
19 votes
2 answers
4k views

Integration analog of automatic differentiation

  • 772
17 votes
3 answers
783 views

How, if at all, does pure mathematics benefit from $2^{74207281}-1$ being prime?

16 votes
1 answer
2k views

Does the "prime ant" ever backtrack?

  • 4,928
16 votes
4 answers
582 views

Graph Isomorphism for non-mathematician

15 votes
1 answer
919 views

Is this condition sufficient to ensure monotonicity of a function?

14 votes
4 answers
1k views

Can multiplication be defined in terms of divisibility?

  • 17.4k
13 votes
2 answers
1k views

Smallest prime in arithmetic progressions: upper bounds?

  • 25.6k
12 votes
2 answers
274 views

Infinitely many polygons, no four have a common point

  • 1,236
12 votes
1 answer
344 views

Biggest Little Polyhedron

  • 19.6k
12 votes
4 answers
4k views

Does DTIME(O(n)) = REGULAR?