OFFSET
1,2
COMMENTS
Arithmetic progression is stopped when next term is not prime. E.g. for n=3, a=3, that is 7,13,19 are prime, while next term, 25, is not prime.
MATHEMATICA
bb={}; Do[s=1; Do[If[PrimeQ[7+k*d], s=s+1, bb={bb, s}; Break[]], {k, 10}], {d, 2, 200, 2}]; Flatten[bb]
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Zak Seidov, Sep 29 2003
STATUS
approved