login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

a(n) = least positive k such that Mordell's equation y^2 = x^3 + k has exactly n integral solutions.
20

%I #14 May 02 2017 22:21:15

%S 6,27,2,343,12,1,37,8,24,512,9,35611289,73,10218313,315,129554216,17,

%T 274625,297,17576000,2817,200201625,1737

%N a(n) = least positive k such that Mordell's equation y^2 = x^3 + k has exactly n integral solutions.

%C Additional known terms: a(24)=4481, a(26)=225, a(28)=2089, a(32)=1025.

%C For least positive k such that equation y^2 = x^3 - k has exactly n integral solutions, see A179175.

%C If n is odd, then a(n) is perfect cube. [Ray Chandler]

%H J. Gebel, <a href="/A001014/a001014.txt">Integer points on Mordell curves</a> [Cached copy, after the original web site tnt.math.se.tmu.ac.jp was shut down in 2017]

%Y Cf. A054504, A081119, A179145-A179162.

%K more,nonn

%O 0,1

%A _Artur Jasinski_, Jun 30 2010

%E Edited and a(11), a(13), a(15), a(17), a(19), a(21) added by _Ray Chandler_, Jul 11 2010