Michael Lugo
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 Apr 28 comment You have to estimate $\binom{63}{19}$ in $2$ minutes to save your life. Except the denominator here should be $10^{19}$. Apr 21 answered Distribution of a Gaussian variable with a normally distributed mean Apr 18 comment Stability of a dimer on a square grid after $n$ random steps An observation about the value of using calculations like this to make conjectures: it's easy to see that $P_1 = 3^2/2^4, P_2 = 10^2/2^8, P_3 = 35^2/2^{12}$. So one can conjecture the result from recognizing the sequence $3, 10, 35$ as ${2n + 1 \choose n}$ for $n = 1, 2, 3$. Apr 15 comment Ranking players and puzzles from performance in a single player game format This question seems appropriate to me, but it's really a statistical question. As such it's probably more appropriate for stats.stackexchange.com Apr 13 answered Alternative “Fibonacci” sequences and ratio convergence Apr 13 comment What percentage of prime number factorials plus 1 are themselves prime? The OEIS sequences oeis.org/A088332 and oeis.org/A002981 are relevant. The sequence looks sparse enough that I'd guess the density is 0. The paper by Caldwell and Gallot at utm.edu/staff/caldwell/preprints/primorials.pdf gives a heuristic (Conjecture 2.3) that the number of primes $n! + 1$ with $n \le N$ is asymptotic to $e^\gamma \log N$ as $N \to \infty$. Apr 12 comment How many points to prove a trigonometric identity? In this case, all the trig functions can be expressed in terms of $\exp{i \theta}$ and so both sides are rational functions of $\exp{i \theta}$; thus it should be possible to reduce this to a question about polynomials. Apr 8 awarded Nice Answer Apr 8 answered Does sum of the reciprocals of all the composite numbers converge? Apr 7 comment Generating Numbers Proof I'd note that you also would need to remove trailing zeroes. For example, consider the sequence 19, 38, 76, 152, 304, 30. (You don't have to remove them right away - this could continue 30, 60, 120, 240, 24, 2 or 30, 3, 6, 12, 24, 2 - but I don't see any reason not to remove trailing zeros as they appear.) Apr 1 comment Primes Between $n$ and $2n$ For $n\ge6$ That sequence of primes is called the "Ramanujan primes": see oeis.org/A104272 Mar 31 awarded Sportsmanship Mar 31 reviewed Approve Algorithm/formula for computing the probability of winning a range of games Mar 31 answered Algorithm/formula for computing the probability of winning a range of games Mar 30 comment Asymptotic bounds of product of $\log(i)$ It will suffice to find bounds for the log of your product, $\sum_{k=2}^n \log_2 \log_2 k$, which is done at math.stackexchange.com/questions/1084665/… Mar 29 answered How many base $10$ numbers are there with $n$ digits and an even number of zeros? Mar 29 awarded Nice Answer Mar 24 revised Why is it more efficient to compute the modular exponentiation by calculating to the power of two and not three for example? edited tags Mar 23 revised Lower Growth Rate of Euler Totient Function removed boundary-value-problem tag Mar 23 comment Why is arccos(-1/3) the optimal angle between bonds in a methane (CH4) molecule? As is pointed out at the related question on this site math.stackexchange.com/questions/1663014/… , this is known as the Tammes problem - see e. g. en.wikipedia.org/wiki/Tammes_problem . This is not an answer but it might give you some idea where to look.