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Search options not deleted user 3920

Enumerative combinatorics, graph theory, order theory, posets, matroids, designs and other discrete structures. It also includes algebraic, analytic and probabilistic combinatorics.

15 votes

Sum of 'the first k' binomial coefficients for fixed $N$

Each binomial coefficient satisfies $$\left(\frac{N}{i}\right)^i \leq {N \choose i} < \left(\frac{eN}{i}\right)^i,$$ so if $k \leq N/2$, you can upper bound the sum by $k(\frac{eN}{k})^k$
Justin Melvin's user avatar
9 votes
1 answer
1k views

Vertex connectivity of random graphs?

Consider simple, undirected Erdős–Rényi graphs $G(n,p)$, where $n$ is the number of vertices and $p$ is the probability for each pair of vertices to form an edge. Many properties of these graphs are k …
Justin Melvin's user avatar