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 A238245 #9 Jan 09 2015 08:01:43 %S A238245 20,39,56,71,80,84,95,104,111,116,119,120,156,180,191,224,239,255,284, %T A238245 296,311,320,336,351,359,380,399,404,416,431,444,455,464,471,476,479, %U A238245 480,500,504,551,596,599,624,639,680,695,696,719,720,756,764,791,824 %N A238245 Positive integers n such that x^2 - 22xy + y^2 + n = 0 has integer solutions. %e A238245 39 is in the sequence because x^2 - 22xy + y^2 + 39 = 0 has integer solutions, for example (x, y) = (2, 43). %Y A238245 Cf. A157014 (n = 20), A137881 (n = 104), A077422 (n = 120), A133275 (n = 180). %Y A238245 Cf. A031363, A084917, A237351, A237599, A237606, A237609, A237610, A236330, A236331, A238240. %K A238245 nonn %O A238245 1,1 %A A238245 _Colin Barker_, Feb 20 2014