ArsenBerk

 22 Why do these paths all have the same length? 18 Number of ways two knights can be placed such that they don't attack. 16 Notation for cartesian product except one set? 15 Number of ways of choosing seven children from a classroom of 32 (15 boys, 17 girls) with at least 1 boy 13 Why is my alternate method of calculating scalar products not working?

### Reputation (12,587)

 +10 How to develop patience in mathematics? +10 does Euler's handshaking lemma apply to directed graphs +10 Independence problem: one rook and maximum number of knights on the chessboard $8 \times 8$ +10 Is Partition Formula wrong when dividing 2 into 2 classes?

### Questions (12)

 5 Putting $m$ distinct balls to $n$ identical boxes with each box has at least $2$ balls 4 Short way for upper triangularization 2 contour integral on a line segment 1 Is there any impredicative definition or axiom which has no predicative counterpart? 1 Existence of limit of a function from existence of another limit of a function

### Tags (202)

 242 combinatorics × 103 57 abstract-algebra × 29 147 discrete-mathematics × 87 55 induction × 26 116 graph-theory × 71 48 elementary-set-theory × 22 79 geometry × 37 47 calculus × 18 77 group-theory × 40 43 permutations × 17

### Bookmarks (14)

 1403 Visually stunning math concepts which are easy to explain 237 What are some examples of when Mathematics 'accidentally' discovered something about the world? 101 Can we remove any prime number with this strange process? 81 $6!\cdot 7!=10!$. Is there a natural bijection between $S_6\times S_7$ and $S_{10}$? 76 Conjectures (or intuitions) that turned out wrong in an interesting or useful way