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!)
A247269 Primes p such that p + m^2 is prime for all m in {2,4,6,8,10,12,14,16,18}. 4
163, 409333, 1483087, 1867783, 222640867, 258001837, 371305267, 748576753, 828497443, 1235054137, 2059599067, 5767711867, 5929920613, 8965599883, 9055004953, 9170160343, 9655686727, 9670115977, 9671300983, 10646399437, 12253792783, 12627473917, 19635778453 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
All terms are == 1 mod 6, and == {7, 13} mod 30.
Subsequence of A246842.
LINKS
PROG
(PARI)
forprime(p=1, 10^12, c=0; for(i=1, 9, if(ispseudoprime(p+(2*i)^2), c++); if(!ispseudoprime(p+(2*i)^2), break)); if(c==9, print1(p, ", "))) \\ Derek Orr, Sep 11 2014
(PARI) is(n)=my(t=n%5); if(t!=2 && t!=3, return(0)); forstep(i=4, 18, 2, if(!isprime(n+i^2), return(0))); isprime(n) && isprime(n+4)
p=2; forprime(q=3, 1e12, if(q-p==4 && is(p), print1(p", ")); p=q) \\ Charles R Greathouse IV, Sep 11 2014
CROSSREFS
Sequence in context: A138200 A146504 A306501 * A145741 A247273 A247275
KEYWORD
nonn
AUTHOR
Zak Seidov, Sep 11 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 23 11:27 EDT 2024. Contains 371913 sequences. (Running on oeis4.)