login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A226986 Primes p such that both prevprime(p^2) - 2 and nextprime(p^2) + 2 are also primes. 1
3, 251, 409, 647, 1031, 1669, 6469, 6679, 12043, 18313, 18517, 31583, 31643, 32957, 33479, 33529, 37783, 39733, 40163, 44071, 58441, 67189, 68279, 83009, 83117, 83423, 87671, 90481, 96001, 98479, 112951, 120011, 130211, 149939, 152297, 155663, 156227, 158293 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
MATHEMATICA
Select[Prime[Range[15000]], AllTrue[{NextPrime[#^2, -1]-2, NextPrime[ #^2]+2}, PrimeQ]&] (* Harvey P. Dale, Jun 12 2022 *)
PROG
(PARI) is(n)=isprime(precprime(n^2)-2) && isprime(nextprime(n^2)+2) && isprime(n) \\ Charles R Greathouse IV, Jun 25 2013
CROSSREFS
Sequence in context: A318065 A349644 A124875 * A158351 A025418 A075901
KEYWORD
nonn
AUTHOR
EXTENSIONS
a(3)-a(34) from Giovanni Resta, Jun 13 2013
a(10) inserted by Charles R Greathouse IV, Jun 25 2013
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 09:14 EDT 2024. Contains 371268 sequences. (Running on oeis4.)