A179866 A057330 with duplicates omitted.

2, 1531, 16651, 15514861

Offset

1,1

Links

Table of n, a(n) for n=1..4.

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

Cf. A057330, A005382

Sequence in context: A329775 A226699 A110027 * A296362 A282999 A375845

Adjacent sequences: A179863 A179864 A179865 * A179867 A179868 A179869

Keyword

nonn,more

Author

Vladimir Joseph Stephan Orlovsky, Jan 11 2011

Extensions

Edited by N. J. A. Sloane, Jan 11 2011.

Status

approved