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 A256465 #7 Apr 02 2015 05:22:28 %S A256465 3,7,9,11,17,21,21,23,27,33,37,37,41,45,45,47,53,59,61,65,69,69,69,69, %T A256465 75,85,89,89,93,97,97,99,101,105,109,111,117,121,121,125,133,137,137, %U A256465 137,141,145,145,145,147,155,161,165,173,177,177,177,177,181,185 %N A256465 Number of points in a circle of squared radius n, points on the circle counted half. %H A256465 S. W. P. Steen, <a href="http://dx.doi.org/10.1093/qmath/os-1.1.232">An expression for the number of lattice-points in a circle</a>, Q. J. Math. 1 (1930) 232-235. %F A256465 a(n) = A057655(n) - A004018(n)/2. %Y A256465 Cf. A057655, A004018. %K A256465 nonn,easy %O A256465 1,1 %A A256465 _R. J. Mathar_, Mar 30 2015