# Order of real component group of J_{0}(N)

William Stein
- Table for all N < 1598, and the code to make it.
- Table for N=pq, where p,q are prime,
and the code to make it.

## A Conjecture About the Data

Conjecture (Frank Calegari)
Let m = #odd prime factors of N + {1, if N = 0 mod 8
{0, otherwise.
Then the component group is isomorphic to (Z/2Z)^f, where
f = 2^m - 1.