Douglas S. Stones
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 May9 awarded Popular Question Mar9 awarded Necromancer Dec27 awarded Nice Answer Dec16 awarded Revival Nov20 awarded Revival Nov16 awarded Popular Question Nov11 awarded Nice Answer Nov5 awarded Revival Oct11 comment Perfect numbers less than 10 000 I'm not sure in Maple, but in GAP they can be found using Filtered([1..9999],i->Sum(DivisorsInt(i))=2*i); which returns [ 6, 28, 496, 8128 ]. It's just brute force computation; nothing intelligent. Oct10 comment New hourly rate after a pay raise Does one really get 3 dollars for answering this question? I find that hard to believe. But, if it were true, by crowdsourcing, we don't even need to know any maths to make money. We can just copy/paste the questions here, and copy/paste the answers back for profit. Nice! Sep24 comment Re-write $1 \cdot x$ to $x$. A large chunk of Adriano's proof (and the Prover9 proof) amounts to showing that $(x^{-1})^{-1}=x$. If we can assume this: $$1x=(xx^{-1})x=x(x^{-1}x)=x(x^{-1}(x^{-1})^{-1})=x1=x.$$ Sep23 revised Prove that $\sum_{k=0}^r {m \choose k} {n \choose r-k} = {m+n \choose r}$ edited tags Sep23 revised How to calculate no. of binary strings containg substring “00”? edited tags Sep23 revised How to solve this using using stirling approx? edited tags Sep21 answered Re-write $1 \cdot x$ to $x$. Sep15 comment Show Continuity Using Epsilon Delta Definiton What happens if you attempt to do what it asks? Sep12 answered Is the any application of vector that is only specific to biology or chemistry? Sep12 revised “Monotone Convergence Theorem” $\implies$ “least upper bound property” edited tags Sep12 revised Binomial and series with 2 coefficients Fixed error Sep12 reviewed Leave Open A bijection of Cartesian products