I think there's an error in the content accessed by one of the links you posted in the news post. On http://primes.utm.edu/glossary/xpage/ColbertNumber.html it says:
"Waclaw Sierpinski used modular covers to prove there were infinitely many odd integers k for which k*2^n+1 are prime for all n > 1. It has been conjectured that 78557 is the smallest . . ."
Shouldn't it say that there are infinitely many odd integers k for which k*2^n+1 are COMPOSITE for all n > 1?