%I A046068
%S A046068 1,2,3,4,2,3,8,2,15,10,4,9,4,4,3,60,6,3,4,2,11,6,9,1483,6,3,5,8,3,11,
%T A046068 12,4,3,6,2,5,6,3,7,10,4,5,6,6,7,168,4,3,4,2,9,18,2,7,14,4,5,12,4,3,
%U A046068 12,8,5,12,5,3,6,2,27,14,3,77,16,11,7,20,2,7,12,7,5,4,2,103,14,9,13,4
%N A046068 Second smallest m such that (2n-1)2^m+1 is prime, or -1 if no such value 
               exists.
%C A046068 There exist odd integers 2k-1 such that (2k-1)2^n+1 is always composite.
%D A046068 Ribenboim, P. The New Book of Prime Number Records. New York: Springer-Verlag, 
               pp. 357-359, 1996.
%H A046068 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               RieselNumber.html">Link to a section of The World of Mathematics.</
               a>
%H A046068 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               SierpinskiNumberoftheSecondKind.html">Link to a section of The World 
               of Mathematics.</a>
%Y A046068 Cf. A046067, A046070.
%Y A046068 Sequence in context: A106653 A049865 A070771 this_sequence A166281 A107468 
               A023632
%Y A046068 Adjacent sequences: A046065 A046066 A046067 this_sequence A046069 A046070 
               A046071
%K A046068 nonn
%O A046068 1,2
%A A046068 Eric Weisstein (eric(AT)weisstein.com)