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 A067632 #4 Jun 11 2019 19:16:07 %S A067632 -2116,-768,-500,-324,-240,-196,-192,-180,0,12,16,60,144,320,588,1936 %N A067632 n(n+180) is a square. %C A067632 Rewrite it as s^2 - t^2 = 90^2 to see that there are only finitely many solutions. %D A067632 Albert H. Beiler, Recreations in the Theory of Numbers (2d ed. 1966), pp. 296, 317. %e A067632 588 is included because 588 * (588 + 180) = 451584, the square root of which is 672. %p A067632 isolve(n*(n+180)=m^2); %t A067632 Select[Range[-2200,2200],IntegerQ[Sqrt[#(#+180)]]&] (* _Harvey P. Dale_, Jun 11 2019 *) %K A067632 sign,fini,full %O A067632 0,1 %A A067632 _Harvey P. Dale_, Feb 02 2002