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Primes of the form 7*2^k-1.
1

%I #23 Apr 11 2022 12:54:50

%S 13,223,3583,917503,14680063,3758096383,246290604621823,

%T 1340933598257652751063553648756520535666396731910651903

%N Primes of the form 7*2^k-1.

%H <a href="/index/Pri#riesel">Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime</a>

%t Select[Table[7*2^n-1, {n,0,200}], PrimeQ] (* _Jean-François Alcover_, Mar 20 2011 *)

%Y See A001771 for more terms.

%Y Cf. A158795 [_Vincenzo Librandi_, Mar 28 2009]

%K nonn,nice

%O 1,1

%A _N. J. A. Sloane_, Dec 29 1999

%E 13 inserted by _R. J. Mathar_, Apr 01 2009