Douglas S. Stones
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 Sep9 comment Finding the last two digits of a number by binomial theorem Does, "compute the number" count as any other way? The number is 108347059433883722041830251. Sep7 answered What is the probability of guessing an IP correctly? Sep5 comment Solving a system of equations using modular arithmetic modulo 5 Print(Concatenation([":",")"]),"\n"); Sep5 answered Solving a system of equations using modular arithmetic modulo 5 Sep4 asked Is there a better way to input an $n$-cycle in GAP? Sep3 answered An abelian group of a certain order Sep2 comment Find the sum of all 4-digit numbers formed by using digits 0, 2, 3, 5 and 8? I know how you feel. But it is useful to know how to solve problems computationally too, even if it is just to check human-written solutions. (By the way, what language is this?) Sep2 revised Counting the number of subgraphs isomorphic with the following digraph added 107 characters in body Sep2 answered Can This Matrix Proof Be Done Without the Definition? Sep1 answered Graph Theory / Networks … Triadic Closure and Strong/Weak Ties Aug31 comment In how many ways can three numbers be selected from the numbers $1,2,\dots,300$ such that their sum is divisible by $3$? Aside from the above, I found yours the best answer. Right to the point! Aug31 comment In how many ways can three numbers be selected from the numbers $1,2,\dots,300$ such that their sum is divisible by $3$? I'd say the answer to that question is yes (but I don't know what it is). Aug31 answered In how many ways can three numbers be selected from the numbers $1,2,\dots,300$ such that their sum is divisible by $3$? Aug31 comment In how many ways can three numbers be selected from the numbers $1,2,\dots,300$ such that their sum is divisible by $3$? In the $(0,1,2)$ case, we can choose $100^3$ triples. Aug31 revised Factorising complex equations edited tags Aug31 reviewed Reviewed Want to clarify whether I am correct or not, $\Phi(G) \subseteq \Phi(H)$? Aug30 revised A problem on limit added 137 characters in body Aug30 comment For what $n$ can $\pm 1\pm 2\pm 3 … \pm (n-1) \pm n = n+1$? That's an assertion. Could you add a proof of this assertion into this answer? Aug30 comment Find order of $xy$ provided $x^2=e, y^3=e$ and $yxy=xy^2x$ It's somewhat implicit that saying e.g. "$x^2=e$" implies $x$ has order $2$, otherwise we'd instead say "$x=e$" (or not even introduce $x$). Perhaps I'm a bit too pedantic (but this kind of detail matters e.g. for automated theorem proving). Anyway, the answer is fine so I better +1 it. Aug30 comment Find order of $xy$ provided $x^2=e, y^3=e$ and $yxy=xy^2x$ Hmm... it could be that $x=e=y$ too (in which case $xy=e$ has order $1$). The question doesn't say e.g. "the order of $x$ is $2$". [It must be a divisor of 3, though. So it's either $3$ or $1$.]