ShreevatsaR
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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.