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Jan
11
reviewed Looks OK Find the limit of $\lim_{n\rightarrow\infty}(\frac{1}{2}+\frac{3}{2^2}+…+\frac{2n-1}{2^n})$
Jan
10
answered Combinatorial Identity
Jan
10
answered Finite summation with binomial coefficients, $\sum (-1)^k\binom{r}{k} \binom{k/2}{q}$
Jan
10
reviewed No Action Needed complex coordinates of perpendicular chords on unit circle
Jan
10
reviewed Looks OK Fundamental weights of $A_n$
Jan
10
reviewed Close For the birthday problem, what if a person was chosen beforehand?
Jan
10
revised The smallest $n> 0$ with the nonzero $n$th Stiefel-Whitney class is a power of 2 when total Stiefel-Whitney class is not trivial.
edited tags
Jan
10
comment Are Exponential and Trigonometric Functions the Only Non-Trivial Solutions to $F'(x)=F(x+a)$?
related: math.stackexchange.com/q/199691
Jan
9
revised Finite summation with binomial coefficients, $\sum (-1)^k\binom{r}{k} \binom{k/2}{q}$
more descriptive title
Jan
9
comment Finite summation with binomial coefficients, $\sum (-1)^k\binom{r}{k} \binom{k/2}{q}$
off the top of my head, something like math.stackexchange.com/a/609202 should work (but finding a bijective proof would be, perhaps, more challenging)
Jan
9
comment Finite summation with binomial coefficients, $\sum (-1)^k\binom{r}{k} \binom{k/2}{q}$
@Marko tomorrow (or later) — maybe; if you have time now — please just go ahead
Jan
9
reviewed Looks OK Why schemes are $(X,\mathcal O_X)$ rather than $(\mathcal O_X,X)$ or $\{X,\mathcal O_X\}$
Jan
9
comment A three variable binomial coefficient identity
Thank you! I'm awarding the bounty now — and will try to understand the proof later.
Jan
9
reviewed Close Does $\sum_{n = 2}^{\infty} \frac{\sqrt{n + 1}}{n(n-1)}$ converge or diverge?
Jan
9
comment A three variable binomial coefficient identity
I've also asked a (different but) related question @ MO
Jan
9
reviewed Leave Closed How derivative relates to roots of original function
Jan
9
comment Is this morphism of spectra zero in the stable homotopy category?
No, that generalization is not true: take any non-trivial stable cohomological operation — say, Bockstein $EM(n)\to EM(n+1)$.
Jan
9
reviewed No Action Needed Back to Front Eisenstein - number theory
Jan
8
reviewed Close let $G$ to be group such that $O(G)=p^2$ where $p$ is prime,prove that $G$ is cyclic or $G$ is Direct product of two cyclic subgrops of order $n$.
Jan
8
answered Is this morphism of spectra zero in the stable homotopy category?