OFFSET
1,1
COMMENTS
Sum of the members of the n-th prime triple (p, p+2, p+6).
All terms are congruent to 5 (mod 18). See A242215. - Robert Bilinski, Sep 24 2019
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
FORMULA
EXAMPLE
23 is in the sequence because 23 = 5+7+11 = 3*5+8.
41 is in the sequence because 41 = 11+13+17 = 3*11+8.
MATHEMATICA
8 + 3*Select[Prime[Range[1000]], PrimeQ[# + 2] && PrimeQ[# + 6] &] (* Vincenzo Librandi, Jan 04 2014 *)
PROG
(Magma) [(3*p+8): p in PrimesUpTo(1000)| IsPrime(p+6) and IsPrime(p+2)]; // Vincenzo Librandi, Jan 06 2018
(PARI) is(n)=n%18==5 && isprime(n\3-2) && isprime(n\3) && isprime(n\3+4) \\ Charles R Greathouse IV, Jan 06 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Aug 02 2009
EXTENSIONS
Notation normalized by R. J. Mathar, Aug 07 2009
STATUS
approved