OFFSET
1,1
EXAMPLE
2*2-1=3,2*3-1=5,2*5-1=11;
2,3,5;
1531,3061,6121,12241,24481;
16651,33301,66601,133201,266401,532801,1065601;
15514861,31029721,62059441,124118881,248237761,496475521,992951041,1985902081;
MATHEMATICA
q=1; Reap[Do[lst={a=Prime[n]}; While[PrimeQ[a=2a-1], AppendTo[lst, a]]; If[Length[lst]>q, q=Length[lst]; Print[lst]; Sow[lst[[1]]]], {n, 10^6}]][[2, 1]]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Vladimir Joseph Stephan Orlovsky, Jan 11 2011
EXTENSIONS
Edited by N. J. A. Sloane, Jan 11 2011.
STATUS
approved