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Sune Jakobsen
  • Member for 12 years, 6 months
  • Last seen more than 5 years ago
7 answers
287 votes
19k views
133 bookmarks
Polynomial representing all nonnegative integers
8 answers
183 votes
11k views
99 bookmarks
Two commuting mappings in the disk
4 answers
61 votes
4k views
23 bookmarks
What is the limit of gcd(1! + 2! + ... + (n-1)! , n!) ?
7 answers
42 votes
3k views
25 bookmarks
How would one even begin to try to prove that a simple number-theoretic statement is undecidable?
9 answers
39 votes
3k views
13 bookmarks
The shortest path in first passage percolation
3 answers
29 votes
2k views
12 bookmarks
Improving a sequence of 1s and -1s
5 answers
28 votes
4k views
17 bookmarks
Partial sums of multiplicative functions
2 answers
26 votes
2k views
11 bookmarks
Is there a combinatorial interpretation of the identity $\sum_{k=0}^m 2^{-2k} \binom{2k}{k} \binom{2m-k}{m} =4^{-m} \binom{4m+1}{2m}$?
4 answers
19 votes
2k views
11 bookmarks
How many of the true sentences are provable?
3 answers
15 votes
1k views
6 bookmarks
Is this strange problem NP-complete?
6 answers
11 votes
2k views
6 bookmarks
Which model of computation is "the best"?
3 answers
11 votes
906 views
4 bookmarks
Greatest function satisfying some convexity requirements
3 answers
10 votes
396 views
2 bookmarks
disconnected or poorly connected graphs in sport ratings systems
4 answers
8 votes
5k views
5 bookmarks
Geodesics on a hyperbolic paraboloid
1 answer
7 votes
470 views
1 bookmarks
Combinatorial Problem
5 answers
5 votes
960 views
1 bookmarks
A walk on a compact 2D surface embedded in 3-space that never returns home