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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A236509 Primes p with p + 2, p + 6 and prime(p) + 6 all prime. 2
5, 11, 107, 227, 311, 347, 821, 857, 1091, 1607, 1997, 2657, 3527, 4931, 5231, 8087, 8231, 9431, 10331, 11171, 12917, 13691, 13877, 21377, 22271, 24917, 27737, 29567, 32057, 33347, 35591, 36467, 37307, 39227, 42017 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

According to the conjecture in A236508, this sequence should have infinitely many terms.

LINKS

Zhi-Wei Sun, Table of n, a(n) for n = 1..10000

EXAMPLE

a(1) = 5 since 5, 5 + 2 = 7, 5 + 6 = 11 and prime(5) + 6 = 17 are all prime, but 2 + 2 = 4 and 3 + 6 = 9 are both composite.

MATHEMATICA

p[n_]:=p[n]=PrimeQ[n+2]&&PrimeQ[n+6]&&PrimeQ[Prime[n]+6]

n=0; Do[If[p[Prime[m]], n=n+1; Print[n, " ", Prime[m]]], {m, 1, 10^6}]

CROSSREFS

Cf. A000040, A022004, A023201, A046117, A236464, A236508.

Sequence in context: A090160 A062652 A075706 * A057178 A056265 A302144

Adjacent sequences:  A236506 A236507 A236508 * A236510 A236511 A236512

KEYWORD

nonn

AUTHOR

Zhi-Wei Sun, Jan 27 2014

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 June 15 22:19 EDT 2019. Contains 324145 sequences. (Running on oeis4.)