9,886 reputation
22148
bio website gottwurfelt.wordpress.com
location Atlanta, GA
age 31
visits member for 4 years, 5 months
seen 2 hours ago

Data scientist and math blogger.


Mar
23
answered hypergeometric distribution problem
Mar
22
comment Are there infinitely many $x$ for which $\pi(x) \mid x$?
The clumping makes sense -- there's a clump for $x/\pi(x) = 1$, a clump for $x/\pi(x) = 2$, and so on.
Mar
22
awarded  Electorate
Mar
22
answered What do $\pi$ and $e$ stand for in the normal distribution formula?
Mar
21
comment Sample randomly from (or computably enumerate) non-decreasing sequences from 1 to n of length k
To be honest, this is probably in Knuth.
Mar
21
answered Sample randomly from (or computably enumerate) non-decreasing sequences from 1 to n of length k
Mar
21
comment Logic question: Ant walking a cube
The expected number of steps to reach any vertex, in this case, are all integers. This seems surprising to me; does anyone know a nice reason why?
Mar
20
answered Finding the optimum supply quantity when there is uncertainty in forecast
Mar
19
awarded  Nice Answer
Mar
16
answered Asymptotic number of unlabeled graphs
Mar
12
revised How can I write $\frac{1}{(a+x)}$ as an exponential function $y = Ce^{-kx}$?
added 1280 characters in body
Mar
12
answered How can I write $\frac{1}{(a+x)}$ as an exponential function $y = Ce^{-kx}$?
Mar
12
comment $m$ balls $n$ boxes probability problem
The distinguishable case is easier. This is actually a rephrasing of the "coupon collector problem"; if you've heard of that problem, great, and if it's not, you have another term to search for.
Mar
10
comment Expectation of the maximum of IID geometric random variables
These are very nice principles. I'd just add that what Didier has called "repartition function" is called "cumulative distribution function" in English.
Mar
10
comment Finding the distance between two triangles, one inside the other
Right. But the area of the larger triangle is $(2a)(2b)/2 = 2ab$.
Mar
10
comment Is there an automated way to prove really boring elementary number theoretic results?
@Alex oh, I'm not claiming it's new. But you really don't want me coming up with my own jokes.
Mar
10
comment Is there an automated way to prove really boring elementary number theoretic results?
$x^n + y^n = z^n$ has no solutions in positive integers with $n > 2$. I have a truly remarkable proof of this fact but the comment box is too small to contain it.
Mar
10
comment Finding the distance between two triangles, one inside the other
If we have right triangles with sides $a, b, c$ and $2a, 2b, 2c$, with $c, 2c$ the hypotenuses, then generalizing this algebraic approach gives $t = ab/(a+b+c) = 2ab/(2a+2b+2c)$ -- that is, the area of the larger triangle divided by its perimeter. I was able to show this algebraically; your "quick solution", I think, explains why this should be so.
Mar
10
revised Finding the distance between two triangles, one inside the other
deleted 1 characters in body
Mar
10
comment Finding the distance between two triangles, one inside the other
I meant "bottom left". Sorry.