OFFSET
1,1
COMMENTS
Subsequence of A001359. - R. J. Mathar, Feb 10 2013
All terms are congruent to 5 (mod 6). - Matt C. Anderson, May 22 2015
LINKS
Matt C. Anderson Table of n, a(n) for n = 1..10000 (terms 1..1000 from T. D. Noe)
T. Forbes and Norman Luhn, Prime k-tuplets
R. J. Mathar, Table of Prime Gap Constellations (2013,2024), 275 pages (no not print...)
Thomas R. Nicely, Enumeration of the prime triples (q,q+2,q+6) to 1e16.
P. Pollack, Analytic and Combinatorial Number Theory, Course Notes, p. 132, ex. 3.4.3. [Broken link?]
P. Pollack, Analytic and Combinatorial Number Theory, Course Notes, p. 132, ex. 3.4.3.
Maxie D. Schmidt, New Congruences and Finite Difference Equations for Generalized Factorial Functions, arXiv:1701.04741 [math.CO], 2017.
Eric Weisstein's World of Mathematics, Prime Triplet
MAPLE
A022004 := proc(n)
if n= 1 then
5;
else
for a from procname(n-1)+2 by 2 do
if isprime(a) and isprime(a+2) and isprime(a+6) then
return a;
end if;
end do:
end if;
end proc: # R. J. Mathar, Jul 11 2012
MATHEMATICA
Select[Prime[Range[1000]], PrimeQ[#+2] && PrimeQ[#+6]&] (* Vladimir Joseph Stephan Orlovsky, Mar 30 2011 *)
Transpose[Select[Partition[Prime[Range[1000]], 3, 1], Differences[#]=={2, 4}&]][[1]] (* Harvey P. Dale, Dec 24 2011 *)
PROG
(Magma) [ p: p in PrimesUpTo(10000) | IsPrime(p+2) and IsPrime(p+6) ] // Vincenzo Librandi, Nov 19 2010
(PARI) is(n)=isprime(n)&&isprime(n+2)&&isprime(n+6) \\ Charles R Greathouse IV, Jul 01 2013
(Python)
from sympy import primerange
def aupto(limit):
p, q, alst = 2, 3, []
for r in primerange(5, limit+7):
if p+2 == q and p+6 == r: alst.append(p)
p, q = q, r
return alst
print(aupto(5477)) # Michael S. Branicky, May 11 2021
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved