login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A072060 Smallest prime p such that 2*p+1 has n prime factors (with multiplicity). 2
2, 7, 13, 67, 283, 607, 1093, 12757, 22963, 49207, 482233, 1623847, 797161, 14614627, 19929037, 35872267, 150663523, 2044719247, 1355971711, 9879222469, 37773497677, 200490103057, 172595827849, 235357947067, 1176789735337 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..25.

EXAMPLE

a(4)=67=A000040(19): 2*67+1 = 135 = 5*3^3, 4 factors.

CROSSREFS

Cf. A001222, A023595, A072055, A072059.

Sequence in context: A180003 A211874 A262830 * A106912 A099629 A092836

Adjacent sequences:  A072057 A072058 A072059 * A072061 A072062 A072063

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jun 11 2002

EXTENSIONS

More terms from Don Reble, Apr 15 2003

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 18 00:19 EST 2019. Contains 320237 sequences. (Running on oeis4.)