A260993 - OEIS

%I #12 Aug 10 2015 00:07:32

%S 22,23,26,28,29,30,31,33,35,37,39,40,41,43,46,47,48,50,53,59,61,65,71,

%T 79,83,89,101,131

%N Numbers n such that the modular curve X_0(n) contains infinitely many rational points of degree 2.

%H Francesc Bars, <a href="http://dx.doi.org/10.1006/jnth.1998.2343">Bielliptic Modular Curves</a>, Journal of Number Theory, 76 (1999), 154-165.

%Y Cf. A260990, A260991, A260992, A260994.

%K nonn,fini,full

%O 1,1

%A _N. J. A. Sloane_, Aug 08 2015, following a suggestion from _Roger L. Bagula_, Jul 22 2015