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visits member for 5 years, 3 months
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6h
comment Triangular Billiard Table
Now I'm confused. Is the question inappropriate for MO because it is too easy, or because it is too hard?
9h
comment how many pythagorean triplets can be formed with N given so that addition of all three sides is equal to N?
There is a fair bit of information about Pythagorean perimeters at maths.surrey.ac.uk/hosted-sites/R.Knott/Pythag/… The first $N$ with exactly 35 triplets is 134640.
9h
revised Are there examples of non-orientable manifolds in nature?
edited tags
9h
answered On the number of consecutive divisors of an integer
1d
comment What has happened to Lang's Files and other political texts?
Did you ever find out, Jonathan, whether anyone holds Lang's unpublished works? I ask because I have a number of letters he wrote me in 1967-68-69.
2d
comment Reference request for some “irregularities of distribution” papers
The journal changed its name some time ago to Indag. Math.
May
21
comment Reference for measures of commutativity needed
You might be interested in Geher and Nagy, Maps on classes of Hilbert space operators preserving measure of commutativity, Lin. Alg. and its Appl. 463 (2014) 205-227, which discusses the norm of the commutator, and refers to earlier work.
May
21
comment Reference for measures of commutativity needed
Also posted to m.se, without notification to either site of the other posting: math.stackexchange.com/questions/1291238/…
May
21
comment Searching for $C^*$
The close voters come to bury $C^*$, not to praise it.
May
20
comment On Polynomials dividing Exponentials
The edit today marks the first time that the problem has been presented with a factorial in it. I find it peculiar that it wasn't presented that way five years ago, since the factorial seems to have been in the original publication.
May
20
comment On Polynomials dividing Exponentials
The link doesn't seem to go anywhere any more.
May
20
comment A Diophantine equation with prime powers
This counterexample was in Linus Hamilton's comment on knsam's (not-a-complete-)answer.
May
20
comment inequality involving determinants and quadratic forms
@Christian, thanks. I'm sure I saw it my way somewhere, but I will change over to the standard way from now on.
May
19
comment inequality involving determinants and quadratic forms
As $A$ is symmetric positive semidefinite, you must have $\lambda_{\rm min}=0$, no?
May
19
comment Numbers represented by inhomogeneous forms
$a(y,z)=yz-y-z=(y-1)(z-1)-1$, so the only way to get $a(y,z)=1$ is $\{\,y,z\,\}=\{\,2,3\,\}$.
May
18
comment Counting ways to Arrange Variable Sized Objects into Fixed Number of Spaces
Does $1+2$ count as different from $2+1$? If yes, then I think you write down a simple (homogeneous, constant-coefficient, linear) recurrence relation, etc. If no, then I think you are asking about the number of partitions of $n$ into parts of size at most $i$, a much-studied problem. Either way, I don't see a research angle to the question, so I don't think it's suited for MO. I'd recommend clarifying the question, maybe including a couple of examples to help people understand what you want, and then posting it somewhere else.
May
17
comment Mathematical research papers in general science journals
OP specifically excludes PNAS in the 1st paragraph of the question.
May
16
revised how to evaluate the following double summation to infinity without using integration method?
typo in title
May
14
revised Modern Mathematical Achievements Accessible to Undergraduates
deleted improper apostrophe
May
12
comment Enumerating ways to decompose an integer into the sum of two squares
As you are counting decompositions of the form $0^2+a^2$, shouldn't a power of 4 return 1, not 0?