# via Yousuke Koide
n=724: c260(6294274828......) = 22780106292572351730658730234738216404394547689 * p214(2763057708......)
# GMP-ECM
n=527: c463(2403430536......) = 12608116535176707758425943211733416917 * c426(1906256600......)