

A136721


Prime quadruples: 3rd term.


2



11, 17, 107, 197, 827, 1487, 1877, 2087, 3257, 3467, 5657, 9437, 13007, 15647, 15737, 16067, 18047, 18917, 19427, 21017, 22277, 25307, 31727, 34847, 43787, 51347, 55337, 62987, 67217, 69497, 72227, 77267, 79697, 81047, 82727, 88817, 97847
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OFFSET

1,1


COMMENTS

Primes p such that p6, p4, and p+2 are prime. Apart from the first term, a(n) = 17 (mod 30).
The members of each quadruple are twin primes when they are 1st and 2nd terms and when 3rd and 4th terms. When they are 2nd and 3rd terms they differ by 4.


LINKS

Robert Israel, Table of n, a(n) for n = 1..10000


FORMULA

a(n) = A007530(n)+6 = A136720(n)+4 = A090258(n)2.  Robert Israel, Oct 11 2019


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 [p2p1, p3p2, p4p3] = [2, 4, 2] then
count:= count+1; Res:= Res, p3
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, p6]]]], {n, 12^4}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 22 2008 *)


CROSSREFS

Cf. A007530, A090258, A136720.
Sequence in context: A250716 A244853 A102870 * A107172 A090286 A226677
Adjacent sequences: A136718 A136719 A136720 * A136722 A136723 A136724


KEYWORD

easy,nonn


AUTHOR

Enoch Haga, Jan 18 2008


EXTENSIONS

Edited by Charles R Greathouse IV, Oct 11 2009


STATUS

approved



