435 reputation
513
bio website in.another.dimension
location Athens, Greece
age 46
visits member for 3 years, 10 months
seen 6 hours ago

Interests: math, programming and games, not necessarily in that order.

Favourite numbers: Surreals


Nov
6
comment Reference request for unknown mathematical constant
Using $\frac{1}{m(m+1)^2} = \frac{1}{m} - \frac{1}{m+1} - \frac{1}{(m+1)^2}$
Nov
6
comment Does the A001921 linear recurrent integer sequence always yield composite numbers?
Why you considered $a(64n+17)$ and not $a(64n+33)$?
Nov
6
comment Union of power sets of the counting numbers
It's an infinite set that its elements are finite.
Nov
6
comment Prove that $\frac{1}{a^3(b+c)}+\frac{1}{b^3(a+c)}+\frac{1}{c^3(a+b)}\ge \frac32$
How will you use the Cauchy-Schwarz? Do you mean the AM-GM inequality perhaps?
Nov
6
comment Proving that $\frac{\pi ^2}{p}\neq \sum_{n=1}^{\infty }\frac{1}{a_{n}^2}$
What are the $a(n)$? Are you asking to prove that no sequence of positive integers can have this as result?
Nov
6
revised does $\int_0^\infty x/(1+x^2 \sin^2x) \mathrm dx$ converge or diverge?
Perhaps this is a better presentation of the proof's logic
Nov
6
suggested approved edit on does $\int_0^\infty x/(1+x^2 \sin^2x) \mathrm dx$ converge or diverge?
Nov
4
comment “Negative” versus “Minus”
Why is this question protected and not closed as off-topic? It could well fit to Mathematics Education site, but not here in my opinion.
Nov
4
comment Why is $Z_2 \times Z_3 \times Z_4$ not isomorphic to $Z_{24}$?
Do 2 and 4 share no common factor?
Nov
4
comment How would you show that $\sqrt{14+4\sqrt{10}} - \sqrt{14-4\sqrt{10}} = 4$?
Nice. One could also prove first that (for $0<b<a$) this is true: $ \sqrt{a + b +- 2\sqrt a \sqrt b} = \sqrt a +- \sqrt b $ and then use it with $a=10$ and $b=4$
Nov
4
comment Does $A193201$ count the partitions of $n$ of arbitrary dimension?
I get 14 for n=6. I might have not understood what exactly we are counting. This?: A119268
Nov
3
comment Examples of mathematical discoveries which were kept as a secret
@DavidRicherby I think you could add it as a separate answer. While belonging to the same area (security/cryptography), it is a different discovery.
Nov
3
comment How many possible color combinations?
I don't think there is a closed formula for T(n,m).
Nov
3
revised How many possible color combinations?
deleted 1 character in body
Nov
3
answered How many possible color combinations?
Nov
3
comment How many possible color combinations?
I think the answer is 17952, let me check a few things.
Nov
2
comment Combinatorial prime problem
The smallest I found to need a power of 10 are: 799 = 2^10 - 3^2 * 5^2 and 851 = 3 * 5^4 - 2^10
Nov
2
comment Combinatorial prime problem
797 = 2^5 * 5*2 - 3
Nov
2
comment Prove $\left|\frac{z_1}{z_2}\right|=\frac{|z_1|}{|z_2|}$ for two complex numbers
Where did that square root come from? Can't you use that |z| = r when z = r(cosθ+isinθ)?
Nov
2
comment Proving two graphs are isomorphic in polynomial time - Bondy/Murty - Graph Theory Page 6
It works without a hitch because the graph has a lot of symmetries (self isomorphisms). I think you could identify any 5-cycle with any other (as a start) and it will work.