I also downloaded Python (ver. 2.4.2 window), in command mode when I typed prime = (28433 * (2 ** 7830457) + 1) it finished in about one second. I timed it using handheld stopwatch.
very fast for prime = (28433 * (4 ** 7830457) + 1) prime = (28433 * (8 ** 7830457) + 1) prime = (28433 * (16 ** 7830457) + 1) but it take forever to compute prime = (28433 * (3 ** 7830457) + 1) apparently, there is some clever method to calculate 2&^ ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
