A129931 - OEIS

%I #4 Oct 31 2013 12:17:43

%S 4594309,4921129,5495989,7093057,14722021,23008891,23380471,24251167,

%T 24296563,49201981,51788797,62123011,64649503,69326779,78274321,

%U 88022797,95575771,100099267,125796127,128185777,129299011,130858711

%N Numbers n such that n remains prime through 7 iterations of function f(x) = 2x + 5.

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

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

%K nonn

%O 1,1

%A _Ray G. Opao_, Jun 06 2007

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