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 A309142 #23 Apr 08 2020 07:52:53
%S A309142 0,1,0,0,1,1,0,0,1,0,0,0,0,0,0,0,1,0,0,1,1,1,0,0,1,1,0,1,1,0,0,0,1,1,
%T A309142 1,0,0,0,1,0,0,0,1,1,1,1,0,1,0,1,0,0,1,1,1,0,0,1,0,1,1,1,0,1,2,1,1,0,
%U A309142 0,0,0,0,1,0,1,1,1,0,0,0,1,0,1,1,1,1,1,0,1,0,1
%N A309142 Rank of elliptic curve y^2 = x^3 + (n^2 - 6*n -3)*x^2 + 16*n*x.
%C A309142 a(n) is undefined for n = 0, 1 or 9.
%H A309142 Jinyuan Wang, <a href="/A309142/b309142.txt">Table of n, a(n) for n = 10..5000</a>
%H A309142 Andrew Bremner, Richard K. Guy, Richard J. Nowakowski, <a href="https://doi.org/10.1090/S0025-5718-1993-1189516-5">Which integers are representable as the product of the sum of three integers with the sum of their reciprocals?</a>, Math. Comp. 61 (1993), 117-130.
%H A309142 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>
%o A309142 (PARI) {a(n) = ellanalyticrank(ellinit([0, n^2-6*n-3, 0, 16*n, 0]))[1]}
%Y A309142 Cf. A085514, A086446, A309143, A309144, A309146.
%K A309142 nonn
%O A309142 10,65
%A A309142 _Seiichi Manyama_, Jul 14 2019