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A093007 First nonprime number reached when iterating n under x->2*x+1. 2
1, 95, 15, 4, 95, 6, 15, 8, 9, 10, 95, 12, 27, 14, 15, 16, 35, 18, 39, 20, 21, 22, 95, 24, 25, 26, 27, 28, 119, 30, 63, 32, 33, 34, 35, 36, 75, 38, 39, 40, 335, 42, 87, 44, 45, 46, 95, 48, 49, 50, 51, 52, 215, 54, 55, 56, 57, 58, 119, 60, 123, 62, 63, 64, 65, 66, 135 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

n>1: A070939(a(n))=A070939(n)+A063377(n), A000120(a(n))=A000120(n)+A063377(n).

LINKS

Table of n, a(n) for n=1..67.

EXAMPLE

n=41=A000040(13) -> 2*41+1=83=A000040(23) ->

2*83+1=167=A000040(39) -> 2*167+1=335=67*5, therefore a(41)=335,

A063377(41)=3.

MATHEMATICA

Table[NestWhile[2#+1&, n, PrimeQ], {n, 70}] (* Harvey P. Dale, Sep 25 2012 *)

CROSSREFS

Cf. A093009, A038699.

Sequence in context: A281138 A127457 A281325 * A033415 A300007 A067266

Adjacent sequences:  A093004 A093005 A093006 * A093008 A093009 A093010

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Mar 14 2004

EXTENSIONS

Definition corrected by Harvey P. Dale, Sep 25 2012

STATUS

approved

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Last modified April 18 11:10 EDT 2019. Contains 322209 sequences. (Running on oeis4.)