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 A108380 #8 Mar 12 2017 16:43:40 %S A108380 1,1,1,1,2,1,2,3,2,3,5,5,6,6,4,5,5,5,7,7,10,5,8,7,12,7,10,9,14,13,11, %T A108380 7,14,11,17,9,18,14,18,9,19,12,17,15,14,14,22,15,16,20,20,17,18,22,23, %U A108380 17,24,19,26,21,29,18,26,19,26,31,30,27,31,17,32,23,34 %N A108380 Least number of distinct n-th roots of unity summing to the smallest possible nonzero magnitude. %C A108380 Myerson writes about the unsolved problem of finding a good lower bound on the least magnitude as a function of n. Note that a(n)<n/2 for n>2 because the sum of all n-th roots of unity is 0. %H A108380 Gerald Myerson, <a href="http://www.jstor.org/stable/2323469">How small can a sum of roots of unity be?</a>, Amer. Math. Monthly, Vol. 93 (1986), No. 6, 457-459. %H A108380 T. D. Noe, <a href="http://www.sspectra.com/math/A108380.gif">Plot of the least magnitude for n<=81</a> %e A108380 a(8)=3 because the least nonzero magnitude is sqrt(2)-1, which is the sum of three 8th roots of unity. %Y A108380 Cf. A103314 (number of subsets of the n-th roots of unity summing to zero). %K A108380 nonn %O A108380 1,5 %A A108380 _T. D. Noe_, Jun 01 2005, extended Jun 04 2005