A more general method by which all adequately large numbers may be scrutinized for whether or not they are prime
This is similar to E718, using idoneal numbers to find large primes. This time, Euler gets 11,866,009 and 18,518,809.
Original Source Citation
Nova Acta Academiae Scientiarum Imperialis Petropolitanae, Volume 14, pp. 11-51.
Opera Omnia Citation
Series 1, Volume 4, pp.360-394.