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 A309069 #8 Jul 10 2019 10:29:24
%S A309069 1,3,15,427,17353
%N A309069 Least k such that the rank of the elliptic curve y^2 = x^3 + k^2 is n.
%o A309069 (PARI) {a(n) = my(k=1); while(ellanalyticrank(ellinit([0, 0, 0, 0, k^2]))[1]<>n, k++); k}
%Y A309069 Cf. A031507, A060950, A309060, A309068.
%K A309069 nonn,more
%O A309069 0,2
%A A309069 _Seiichi Manyama_, Jul 10 2019