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

 

Logo

Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A294730 Smallest average >= 6 of a twin prime pair that has exactly 2*n divisors, 0 if no such pair exists. 1
6, 12, 30, 0, 60, 192, 270, 180, 240, 0, 420, 0, 2112, 1620, 1320, 0, 2340, 786432, 3120, 4800, 15360, 0, 3360, 388962, 724992, 6300, 29760, 0, 12240, 0, 7560, 617472, 47382528, 81648, 21600, 0, 651952128, 995328, 21840, 0, 33600, 0, 138240 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

COMMENTS

It is conjectured that a(n)=0 for prime n with the only exceptions given by n=A181490(k)+1, i.e. a(2)=6, a(3)=12, a(7)=192 and a(19)=786432 are the only currently known exceptions.

LINKS

Table of n, a(n) for n=2..44.

CROSSREFS

Cf. A014574, A068525, A075590, A181490.

Sequence in context: A223346 A109510 A034715 * A079390 A124679 A242949

Adjacent sequences:  A294727 A294728 A294729 * A294731 A294732 A294733

KEYWORD

nonn

AUTHOR

Hugo Pfoertner, Nov 08 2017

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 December 11 10:48 EST 2018. Contains 318049 sequences. (Running on oeis4.)