Solution of the Week #327 - False Conjecture

The 58th number: 64,320,987,654,320,987,654,320,987,654,320,987,654,320,987,654,320,987,654,321

is the first in the sequence to be prime.

 

The 40th number: 44,320,987,654,320,987,654,320,987,654,320,987,654,321

is tempting as it doesn’t have any prime factors smaller than 78 million, but it is in fact composite.

Several others only have two prime factors.