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Jan
29
awarded  Nice Answer
Jan
20
comment Mathematics understood through poems?
Updating the broken links: maa.org/press/periodicals/convergence/… maa.org/press/periodicals/convergence/… etc.
Dec
15
comment Expected Number of Coin Tosses to Get Five Consecutive Heads
I found an answer using martingales here: quora.com/… but I'm curious if there is a generating functions way (also about the distribution, say variance or number of trials until 90% probability of seeing what we want).
Dec
15
comment Expected Number of Coin Tosses to Get Five Consecutive Heads
Do you know how to find the distribution (or expectation and variance) for the number of tosses until either 5 consecutive heads or 5 consecutive tails? (Or 5 consecutive equal results from rolling dice.) Is there a question on math.se about this?
Dec
14
awarded  Guru
Dec
9
revised Recurrence relations on a continuous domain
replace with another copy of link I had earlier (page numbers match, better typesetting, corrections) hopefully this link won't die so soon
Dec
4
awarded  Popular Question
Nov
13
comment $e^{e^{e^{79}}}$ and ultrafinitism
@FanZheng Bases don't have to be integers; see Wikipedia articles on Non-integer representation and base-φ. For the rest, I've already explained the issue in my previous comments; I don't know which part is unclear. You might also want to look at this question which is about the "every base is base 10" joke.
Oct
21
awarded  Nice Answer
Sep
11
comment Is this Batman equation for real?
I just found out that the curve was devised by J. Mathew Register (then "teaching at a few art schools throughout the greater Sacramento area", now "a full time professor over at American River College"): quora.com/Who-wrote-the-Batman-equation/answer/…
Aug
13
awarded  Necromancer
Jul
31
awarded  Nice Answer
Jul
27
awarded  Yearling
Jul
27
comment Recurrence relation with generating function problem
I agree; that's part of why it's less simple in this case.
Jul
22
comment Fast way to get a position of combination (without repetitions)
@van E.g. on SO: stackoverflow.com/questions/3143142/… stackoverflow.com/questions/5307222/… (and many others). On this site: math.stackexchange.com/questions/349924/… (and many others). On Wikipedia: en.wikipedia.org/wiki/Combinatorial_number_system en.wikipedia.org/wiki/Factorial_number_system Terms to search for are "(ranking|indexing) combinations", also "combinadics", and names of those WP articles.
Jul
22
comment Simple string permutations question
The answer is correct, but if you're writing it up for homework / an exam etc., you should add that $\binom{5}{2}$ is the number of ways to allocate the positions of the vowels in the sequence.
Jul
22
comment Playing roulette
@nknj: Thanks, fixed.
Jul
22
revised Playing roulette
had switched signs
Jul
21
comment Fast way to get a position of combination (without repetitions)
This question has been asked before multiple times on both this website and StackOverflow; one of the existing answers may suit you. (That's assuming that your $\left(\!\!\binom{n}{k}\!\!\right)$ is just an odd way of writing $\binom{n}{k}$ because I don't know what else it could mean.)
Jul
15
comment What is the most efficient numerical base system?
@alex.jordan: Indeed, looks like I made exactly that mistake, thanks for pointing it out.