login
A173088
Numbers k such that 6*k - 1, 6*k + 1, 6*k + 29, and 6*k + 31 are primes.
1
2, 5, 7, 12, 18, 25, 33, 40, 47, 72, 95, 138, 170, 172, 177, 215, 242, 278, 333, 347, 352, 373, 385, 443, 495, 550, 555, 560, 588, 637, 670, 688, 705, 707, 753, 975, 1045, 1110, 1127, 1243, 1260, 1433, 1495, 1502, 1572, 1668, 1673, 1712, 1717, 1738, 1750, 1810
OFFSET
1,1
COMMENTS
Numbers n such that n and n+5 are both in A002822.
LINKS
EXAMPLE
A002822 starts 1,2,3,5,7,10,12,17,18,23,... Hence the first terms are 2 (7 is in A002822), 5 (10 is in A002822), 7 (12 is in A002822), 12 (17 is in A002822), 18 (23 is in A002822).
MAPLE
# From R. J. Mathar, Mar 01 2010: (Start)
isA002822 := proc(n)
if isprime(6*n-1) and isprime(6*n+1) then
true;
else
false;
end if;
end proc:
isA173088 := proc(n)
isA002822(n) and isA002822(n+5) ;
end proc:
for n from 1 to 1700 do
if isA173088(n) then
printf("%d, ", n) ;
end if;
end do ; # (End)
MATHEMATICA
Select[Range[2000], And @@ PrimeQ[6*# + {-1, 1, 29, 31}] &] (* Amiram Eldar, Jan 01 2020 *)
PROG
(Magma) A002822:=[ k: k in [1..3000] | IsPrime(6*k-1) and IsPrime(6*k+1) ]; [ p: p in A002822 | p+5 in A002822 ]; // Klaus Brockhaus, Mar 01 2010
CROSSREFS
Cf. A002822 (numbers n such that 6*n-1, 6*n+1 are twin primes).
Sequence in context: A359339 A023668 A023564 * A005895 A238661 A135525
KEYWORD
nonn
AUTHOR
EXTENSIONS
Edited, corrected and extended by Klaus Brockhaus, R. J. Mathar and N. J. A. Sloane, Mar 03 2010
Edited by Charles R Greathouse IV, Mar 24 2010
STATUS
approved