OFFSET
1,1
COMMENTS
A subsequence of A022004 (= initial members of prime triples (p, p+2, p+6)). - Emeric Deutsch, Jul 12 2009
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
FORMULA
a(n) == 5 (mod 6). - Hugo Pfoertner, Sep 06 2024
a(n) = (A376013(n) - 8)/3. - Amiram Eldar, Sep 06 2024
a(n) >> n log^4 n. - Charles R Greathouse IV, Sep 19 2024
EXAMPLE
(5,7,11) => 23 is prime.
MAPLE
a := proc (n) if isprime(n) = true and isprime(n+2) = true and isprime(n+6) = true and isprime(3*n+8) = true then n else end if end proc: seq(a(n), n = 1 .. 50000); # Emeric Deutsch, Jul 12 2009
MATHEMATICA
Select[Select[Partition[Prime[Range[4000]], 3, 1], Differences[#] == {2, 4} &], PrimeQ[Total[#]] &][[;; , 1]] (* Amiram Eldar, Sep 06 2024 *)
PROG
(PARI) list(lim)=my(v=List(), p=5, q=7, s); forprime(r=11, lim+6, if(r-p==6 && q-p==2 && isprime(s=3*p+8), listput(v, p)); p=q; q=r); Vec(v) \\ Charles R Greathouse IV, Sep 19 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Milton L. Brown (miltbrown(AT)earthlink.net), Jun 24 2009
EXTENSIONS
Definition corrected by Emeric Deutsch, Jul 12 2009
Extended by Emeric Deutsch, Jul 12 2009
STATUS
approved