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 A110620 #9 Nov 05 2024 12:16:46 %S A110620 0,0,0,0,0,0,0,0,0,0,3,0,0,6,8,0,4,0,3,4,6,0,0,6,0,5,4,0,0,8,0,4,4,4, %T A110620 3,4,4,5,4,4,0,6,1,2,8,2,0,6,4,8,2,2,1,6,4,6,7,3,0,0,1,4,6,4,2,12,1,0, %U A110620 2,4,0,6,2,0,12,1,6,4,1,8,0,2,1,6,2,0,0,1,3,16,4,3,0,2,0,8,0,6,11,4,1,12,0 %N A110620 Number of elliptic curves (up to isomorphism) of conductor n. %H A110620 J. E. Cremona, <a href="/A110620/b110620.txt">Table of n, a(n) for n = 1..10000</a> %H A110620 A. Brumer and J. H. Silverman, <a href="https://doi.org/10.1007/BF02567942">The number of elliptic curves over Q with conductor N</a>, Manuscripta Math. 91 (1996), no. 1, 95-102. %H A110620 J. E. Cremona, <a href="https://johncremona.github.io/ecdata/">Elliptic Curve Data</a>. %H A110620 LMFDB, <a href="https://www.lmfdb.org/EllipticCurve/Q/">Elliptic curves over Q</a>. %e A110620 a(11)=3 since there are three non-isomorphic elliptic curves of conductor eleven, represented by the minimal models y^2+y=x^3-x^2-10*x-20, y^2+y=x^3-x^2-7820*x-263580 and y^2+y=x^3-x^2. %o A110620 (Sage) # Uses Cremona's database of elliptic curves (works for all n < 500000) %o A110620 def a(n): %o A110620 return CremonaDatabase().number_of_curves(n) # _Robin Visser_, Nov 04 2024 %Y A110620 Cf. A005788, A060564. %K A110620 nonn %O A110620 1,11 %A A110620 _Steven Finch_, Sep 14 2005