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A163635
a(n) = 3*A022004(n) + 8.
1
23, 41, 59, 131, 311, 329, 581, 689, 941, 1049, 1391, 1931, 2471, 2579, 2651, 3281, 3839, 3911, 4289, 4451, 4469, 4829, 5621, 5999, 6251, 6719, 6809, 7979, 8069, 9761, 10391, 10589, 11021, 11759, 12011, 12389, 13559, 13919, 14369, 14801
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
FORMULA
a(n) = A022004(n) + (A022004(n)+2) + (A022004(n)+6);
a(n) = A022004(n) + A073648(n) + A098412(n).
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