Elementary functions with zeros only at the positive integers - MathOverflow most recent 30 from http://mathoverflow.net2013-05-25T09:43:23Zhttp://mathoverflow.net/feeds/question/23946http://www.creativecommons.org/licenses/by-nc/2.5/rdfhttp://mathoverflow.net/questions/23946/elementary-functions-with-zeros-only-at-the-positive-integersElementary functions with zeros only at the positive integersFredrik Johansson2010-05-08T18:42:08Z2010-05-08T21:36:48Z
<p>Does there exist a (meromorphic) elementary function $f(z)$ that is zero at all the positive integers $z = 1, 2, 3, \ldots$ and only at those points?</p>
<p>Edit: an <a href="http://en.wikipedia.org/wiki/Elementary_function" rel="nofollow">elementary function</a> can be written as a finite composition of constants, rational functions, exponentials and logarithms.</p>
<p>Obviously a function with those zeros can be constructed using the gamma function or a Weierstrass product, but the question is whether there is an elementary function.</p>
http://mathoverflow.net/questions/23946/elementary-functions-with-zeros-only-at-the-positive-integers/23947#23947Answer by rpotrie for Elementary functions with zeros only at the positive integersrpotrie2010-05-08T18:45:22Z2010-05-08T18:45:22Z<p>I don´t completely understand what you mean by elementary, but you can look at <a href="http://en.wikipedia.org/wiki/Weierstrass_factorization_theorem" rel="nofollow">http://en.wikipedia.org/wiki/Weierstrass_factorization_theorem</a>. Sorry if the question had not to do with this. </p>
http://mathoverflow.net/questions/23946/elementary-functions-with-zeros-only-at-the-positive-integers/23948#23948Answer by Dylan Thurston for Elementary functions with zeros only at the positive integersDylan Thurston2010-05-08T18:45:39Z2010-05-08T18:45:39Z<p>$1/\Gamma(1-z)$.</p>