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Sune Jakobsen
  • Member for 12 years, 7 months
  • Last seen more than 5 years ago
288 votes
7 answers
20k views

Polynomial representing all nonnegative integers

183 votes
8 answers
11k views

Two commuting mappings in the disk

  • 52.9k
61 votes
4 answers
4k views

What is the limit of gcd(1! + 2! + ... + (n-1)! , n!) ?

41 votes
7 answers
3k views

How would one even begin to try to prove that a simple number-theoretic statement is undecidable?

  • 27.6k
39 votes
9 answers
3k views

The shortest path in first passage percolation

  • 23.5k
29 votes
3 answers
2k views

Improving a sequence of 1s and -1s

  • 27.6k
28 votes
5 answers
4k views

Partial sums of multiplicative functions

  • 27.6k
26 votes
2 answers
2k views

Is there a combinatorial interpretation of the identity $\sum_{k=0}^m 2^{-2k} \binom{2k}{k} \binom{2m-k}{m} =4^{-m} \binom{4m+1}{2m}$?

  • 1,858
20 votes
4 answers
2k views

How many of the true sentences are provable?

  • 4,422
15 votes
3 answers
1k views

Is this strange problem NP-complete?

  • 27.6k
11 votes
6 answers
2k views

Which model of computation is "the best"?

11 votes
3 answers
906 views

Greatest function satisfying some convexity requirements

10 votes
3 answers
396 views

disconnected or poorly connected graphs in sport ratings systems

  • 201
8 votes
4 answers
5k views

Geodesics on a hyperbolic paraboloid

7 votes
1 answer
471 views

Combinatorial Problem

  • 73
5 votes
5 answers
961 views

A walk on a compact 2D surface embedded in 3-space that never returns home

  • 771