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 A216500 #6 Sep 11 2012 11:10:41 %S A216500 1,4,9,16,25,36,49,64,81,100,121,144,169,193,196,225,256,289,324,337, %T A216500 361,400,441,457,484,529,576,625,673,676,729,772,784,841,900,961,1009, %U A216500 1024,1033,1089,1129,1156,1201,1225,1296,1297,1348,1369,1444,1521,1600,1681,1737,1764,1801,1828,1849,1873,1936,2017 %N A216500 Numbers which are simultaneously of the form x^2+y^2, x^2+2y^2, x^2+3y^2, x^2+7y^2, all with x>=0, y>=0. %Y A216500 Union of A216451 and the squares (A000290). %K A216500 nonn %O A216500 1,2 %A A216500 _V. Raman_, Sep 07 2012 %E A216500 Edited by _N. J. A. Sloane_, Sep 11 2012