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 A309143 #9 Jul 14 2019 11:56:18 %S A309143 74,141,194,199,202,227,228,234,268,294,310,323,326,338,353,379,381, %T A309143 387,434,439,455,461,462,464,467,494,499,519,522,526,532,535,542,555, %U A309143 561,563,588,599,606,613,617,619,632,654,669,737,753,774,781,793,818,851,858,873 %N A309143 Numbers k for which rank of the elliptic curve y^2=x^3+(k^2-6*k-3)*x^2+16*k*x is 2. %H A309143 Allan J. MacLeod, <a href="http://web.archive.org/web/20100125135648/http://maths.paisley.ac.uk/allanm/ECRNT/knight/knintro.htm">Knight's Problem</a> %F A309143 A309142(a(n)) = 2. %o A309143 (PARI) for(k=10, 1e3, if(ellanalyticrank(ellinit([0, k^2-6*k-3, 0, 16*k, 0]))[1]==2, print1(k", "))) %Y A309143 Cf. A309142. %K A309143 nonn %O A309143 1,1 %A A309143 _Seiichi Manyama_, Jul 14 2019