OFFSET
1,1
COMMENTS
Primes p such that p-2, p+4, and p+6 are prime. Apart from the first term, a(n) = 13 (mod 30).
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
FORMULA
EXAMPLE
The four terms in the first quadruple are 5,7,11,13 and in the 2nd 11,13,17,19. The four terms or members of each set must be simultaneously prime.
MAPLE
p2:= 0: p3:= 0: p4:= 0:
Res:= NULL: count:= 0:
while count < 100 do
p1:= p2; p2:= p3; p3:= p4;
p4:= nextprime(p4);
if [p2-p1, p3-p2, p4-p3] = [2, 4, 2] then
count:= count+1; Res:= Res, p2
fi
od:
Res; # Robert Israel, Oct 11 2019
MATHEMATICA
lst={}; Do[p0=Prime[n]; If[PrimeQ[p2=p0+2], If[PrimeQ[p6=p0+6], If[PrimeQ[p8=p0+8], AppendTo[lst, p2]]]], {n, 12^4}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 22 2008 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Enoch Haga, Jan 18 2008
EXTENSIONS
Edited by Charles R Greathouse IV, Oct 11 2009
STATUS
approved