This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A134518 #7 Jan 25 2016 21:17:45 %S A134518 105,385,2431,2717,8671,17119,19499,20213,20213,34891,34891,93439, %T A134518 93439,93439,93439,93439,282367,282367,282367,282367,282367,282367, %U A134518 282367,282367,282367,617927,617927,849647,849647,849647,849647,849647,874507 %N A134518 Least k such that the cyclotomic polynomial Phi(k,x) contains n or -n as a coefficient, where k is restricted to be the product of 3 distinct prime numbers. %C A134518 It is well-known that k=105 is the first number for which Phi(k,x) has a coefficient other than -1, 0, or 1. See A013594 for the case when k has no restrictions. %H A134518 Jia Zhao and Xianke Zhang, <a href="http://dx.doi.org/10.1016/j.jnt.2010.03.012">Coefficients of ternary cyclotomic polynomials</a>, Journal of Number Theory, Volume 130, Issue 10, October 2010, Pages 2223-2237. %Y A134518 Cf. A007304, A013594. %K A134518 nonn %O A134518 2,1 %A A134518 _T. D. Noe_, Oct 29 2007