%I A040081
%S A040081 2,1,0,0,2,0,1,0,1,1,2,0,3,0,1,1,2,0,1,0,1,1,4,0,3,2,1,3,4,0,1,0,2,1,2,
%T A040081 1,1,0,3,1,2,0,7,0,1,3,4,0,1,2,1,1,2,0,1,2,1,3,12,0,3,0,2,1,4,1,5,0,1,
%U A040081 1,2,0,7,0,1,1,2,2,1,0,3,1,2,0,5,6,1,23,4,0,1,2,3,3,2,1,1,0,1,1,10,0,3
%N A040081 Riesel problem: a(n) = smallest m >= 0 such that n*2^m-1 is prime, or 
               -1 if no such prime exists.
%H A040081 T. D. Noe, <a href="b040081.txt">Table of n, a(n) for n=1..1000</a>
%Y A040081 Cf. A038699 (primes obtained), A050412, A052333.
%Y A040081 Cf. A046069 (for odd n)
%Y A040081 Sequence in context: A054673 A155103 A048105 this_sequence A113063 A123477 
               A035225
%Y A040081 Adjacent sequences: A040078 A040079 A040080 this_sequence A040082 A040083 
               A040084
%K A040081 nonn
%O A040081 1,1
%A A040081 David W. Wilson (davidwwilson(AT)comcast.net)