Discovered with Prime95, version 25, checked by strong (Miller-Rabin) tests in all 22 prime bases from 2 to 79 with pfgw SCRIPT file, development version 20050213. Candidates were sieved to 1.65e15 with sr2sieve.

This discovery eliminates the last sequence 2^n+k from the dual Sierpinski problem search, proving that 78557 is the smallest dual Sierpinski number, except that there remain 20 large probable primes that are not yet proven primes. The distributed effort "Five or Bust" has been coordinated at www.mersenneforum.org, and details about the search can be found there.

To be completed...