A129932 - OEIS

%I #8 Oct 31 2013 12:17:43

%S 541,1861,109111,119101,131617,895351,1774447,2343037,2906623,3686743,

%T 3686953,4330783,4594309,4921129,4922329,5495989,5654137,6712591,

%U 7093057,7729537,9188623,9842263,10492297,10991983,11270671,12307453

%N Numbers n such that n remains prime through 6 iterations of function f(x) = 2x + 5.

%H Robert G. Wilson v, <a href="/A129932/b129932.txt">Table of a(n) for n = 1..149</a>.

%t fQ[n_] := Union[PrimeQ /@ NestList[2 # + 5 &, n, 6]] == {True}; lst = {}; Do[ p = Prime@n; If[fQ@p, Print@p; AppendTo[lst, p]], {n, 10^7}]; lst (* _Robert G. Wilson v_ *)

%t Select[Range[12400000],And@@PrimeQ/@NestList[2#+5&,#,6]&] (* _Harvey P. Dale_, Sep 09 2012 *)

%Y Cf. A023332, A023304, A023274, A023243.

%K nonn

%O 1,1

%A _Ray G. Opao_, Jun 06 2007

%E More terms from _Robert G. Wilson v_, Jun 06 2007