A129931 - OEIS

A129931

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

4594309, 4921129, 5495989, 7093057, 14722021, 23008891, 23380471, 24251167, 24296563, 49201981, 51788797, 62123011, 64649503, 69326779, 78274321, 88022797, 95575771, 100099267, 125796127, 128185777, 129299011, 130858711

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..22.

MATHEMATICA

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 *)

CROSSREFS

Cf. A023243, A023274, A023304, A023332.

Sequence in context: A104950 A234806 A152964 * A206195 A320210 A320219

Adjacent sequences: A129928 A129929 A129930 * A129932 A129933 A129934

KEYWORD

nonn

AUTHOR

Ray G. Opao, Jun 06 2007

EXTENSIONS

More terms from Robert G. Wilson v, Jun 06 2007

STATUS

approved