- Jerry Rhee added an answer:What is your favourite combinatorial object, or mathematical object you find the most fascinating?
- Peter T Breuer added an answer:Which operations can be constructed using only xy and x+y+z?
- Mohammad Ali Dibaee asked a question:What is an interesting and hot research topic in combinatorial group theory?
- Feng Qi added an answer:What are the values of the special Bell polynomials of the second kind?
- Brian S. Blais added an answer:Can anyone give me an interpretation or link about improper uniform prior as a prior distribution in Bayesian estimation?
- Feng Qi added an answer:Can anyone help me with the inequality for the ratio of two Bernoulli numbers?
- Herbert H H Homeier added an answer:What is the power series expansion at zero of the secant to the power of three?
- Miroslav Rypka added an answer:Can anyone suggest references for Iterated Function Systems and combinatorics: uniqueness of addresses?
- Prasanth G. Narasimha-Shenoi added an answer:Let A & B be two square matrices such that A^2 is not equal to B^2, A is not equal to B but A^3=B^3 & A^2B=AB^2. What is determinant of A^2-B^2?
- Sergey Perepechko added an answer:What is the formula to find the number of simple cycles in a graph? Is this problem NP Complete?
- Mostafa Eidiani added an answer:Which Software Package is the best for computations in Codes over Rings?
- Albert Manfredi added an answer:Can anyone help me find amortized splay tree operation derivation?
- Cheng Tianren asked a question:How do I use the Ptolemy inequality to study the geodesic angle?
- Alina Abraham added an answer:In integral theory, how can you integrate all four perspectives in human development into a model?
- Christopher Landauer added an answer:In terms of combinatorics, could (6677,333,166) be cyclical on the torus?
- Mohan Shrikhande added an answer:Is there a database available on the net of symmetric designs?
- Daniel Crespin added an answer:Spin - could you provide some clarification?
- Feng Qi added an answer:Can anyone help me with a combinatorial interpretation?
- Marcel Van de Vel added an answer:Does the discrete n-circle (n even) admit a partition into n/2 pairs, all with a distinct diameter?
- Henning Meyerhenke added an answer:How close is spectral partitioning to the solution of the min-cut problem?
- Donald beverly Giles asked a question:Is there any interest in a very different spreadsheet algorithm for generating incidence matrices of projective planes?
- Christopher Landauer added an answer:Square Root of a Symmetric Matrices
- Issofa Moyouwou added an answer:Up to now, what is known on (the maximal) domains that guarantee the transitivity of the majority rule?
- Bahattin Yildiz added an answer:What do the three parameters represent i.e. (44,22,10)?
- Daniel Page added an answer:Can anyone suggest some good reference papers for beginners in the field of Combinatorial Design?
- Donald beverly Giles asked a question:Can anyone recommend ways to find a skew starter for a room square of side 667?
- Donald beverly Giles added an answer:Why do mathematicians think that the four colour problem cannot be solved theoretically?
- Sanjib Kuila added an answer:Why does the four colorability of planar graphs not ensure the non-biplanarity of K_9?
- Donald beverly Giles added an answer:Proof of the existence of balanced tournament designs?
- Vitaly Voloshin added an answer:Open problem for anyone: can you color the points?

#### About Combinatorics

Combinatorics is a branch of mathematics concerning the study of finite or countable discrete structures. Aspects of combinatorics include counting the structures of a given kind and size (enumerative combinatorics), deciding when certain criteria can be met, and constructing and analyzing objects meeting the criteria (as in combinatorial designs and matroid theory), finding "largest", "smallest", or "optimal" objects (extremal combinatorics and combinatorial optimization), and studying combinatorial structures arising in an algebraic context, or applying algebraic techniques to combinatorial problems (algebraic combinatorics).

What combinatorial or mathematical object (preferably more elusive ones) fascinate you the most, or are your favourite