Per Alexandersson's user avatar
Per Alexandersson's user avatar
Per Alexandersson's user avatar
Per Alexandersson
  • Member for 14 years, 5 months
  • Last seen this week
280 votes
47 answers
109k views

Examples of unexpected mathematical images

91 votes
14 answers
8k views

Time-saving (technology) tricks for writing papers

35 votes
7 answers
4k views

What problem would you base your mathcoin on?

31 votes
2 answers
2k views

Tiling of the plane with manholes

30 votes
1 answer
1k views

Mysterious symmetry - in search for a bijection

25 votes
5 answers
4k views

Monic polynomial with integer coefficients with roots on unit circle, not roots of unity?

24 votes
1 answer
644 views

Rim hook decomposition and volume of moduli spaces

22 votes
3 answers
3k views

Cardioid-looking curve, does it have a name?

20 votes
1 answer
1k views

Tiling rectangle with trominoes — an invariant

20 votes
1 answer
1k views

Symmetric polynomial from graphs

20 votes
5 answers
2k views

Examples of research on how people perceive mathematical objects

18 votes
2 answers
3k views

Is there some known way to create the Mandelbrot set (the boundary), with an iterated function system?

18 votes
3 answers
2k views

Silly me & Van der Waerden conjecture

17 votes
1 answer
859 views

Proof of certain $q$-identity for $q$-Catalan numbers

16 votes
0 answers
360 views

Combinatorial characterization of intersecting intervals in the plane

15 votes
3 answers
383 views

Bicoloring of $\mathbb{N}^2$, avoiding set of patterns, is the maximal limit density rational?

14 votes
1 answer
555 views

Subdivision of pentagon into six congruent pieces

14 votes
3 answers
1k views

What exact number of domino tilings cannot be realizable?

14 votes
2 answers
1k views

Applications of really large numbers

14 votes
1 answer
560 views

Legendary extra parameters to simplify a counting problem

13 votes
4 answers
2k views

Undecidable puzzles

13 votes
1 answer
418 views

Finding combinatorial models / statistics

12 votes
5 answers
3k views

Hausdorff dimension for invariant measure?

12 votes
3 answers
954 views

What techniques are there to prove Schur positivity?

11 votes
1 answer
937 views

Generalization of Schur polynomials

10 votes
1 answer
397 views

Convex Julia sets

10 votes
2 answers
577 views

Lagrange inversion for power-series with rational powers

9 votes
0 answers
347 views

321-avoiding and parity-alternating permutations

9 votes
0 answers
297 views

Symmetric function transition matrix and a non-conjecture by Clifford and Stanley

9 votes
2 answers
402 views

Certain signed sum over $S_n$

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