C := CremonaDatabase();
intrinsic tam(N1::RngIntElt, N2::RngIntElt)
{
Compute dimension of 2-selmer group for all elliptic curves
with conductor between N1 and N2, and write the result to a file
named 2selmer_N1-N2.
}
F := Open(Sprintf("tam_%o-%o", N1, N2),"w");
for N in [N1..N2] do
for i in [1..NumberOfIsogenyClasses(C, N)] do
t := Cputime();
E := EllipticCurve(C, N, i, 1);
c := &*[TamagawaNumber(E,p[1]) : p in Factorization(N)];
r := Rank(E);
fprintf F, "%o\t%o\t%o\t%o\n", N, i, r, c;
Flush(F);
end for;
end for;
end intrinsic;