OFFSET
1,1
COMMENTS
Because 7 is the only prime congruent to 0 mod 7, it is more efficient to search only for primes that are congruent to 5 mod 7 and then insert 7 as the second term of the sequence (see the second Mathematica program below). - Harvey P. Dale, Jun 24 2017
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
Select[Prime[Range[200]], MemberQ[{0, 5}, Mod[#, 7]]&] (* Vincenzo Librandi, Aug 13 2012 *)
Insert[Select[Prime[Range[500]], Mod[#, 7]==5&], 7, 2] (* Harvey P. Dale, Jun 24 2017 *)
PROG
(Magma) [ p: p in PrimesUpTo(2000) | p mod 7 in {0, 5} ]; // Vincenzo Librandi, Aug 13 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved