OFFSET
1,2
COMMENTS
Subsequence of A018252.
MATHEMATICA
DeleteCases[7 Range[0, 200] + 1, _?PrimeQ]
PROG
(Magma) [n: n in [1..500 by 7] | not IsPrime(n)];
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Aug 31 2017
STATUS
approved