OFFSET
1,1
COMMENTS
A040081(659) not yet found. The index sequence of this one is 1, 13, 23, 43, 59, 88, 127, 148, 659.
800516 was found by Dave Linton in 2004.
LINKS
Ray Ballinger and Wilfrid Keller, Riesel Problem
MATHEMATICA
kmax=8192; k = 0; n = 0; km = k; While[k < kmax, n++; k = 0; cp = n*(2^k) - 1; While[(!PrimeQ[cp]) && (k < kmax), k++; cp = n*(2^k) - 1]; If[k > km, km = k; Print[{n, km}]]]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Lei Zhou, Feb 24 2005
EXTENSIONS
Edited by T. D. Noe, Nov 15 2010
STATUS
approved