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Number of primes in arithmetic progression starting with 17 and with d=2n.
9

%I #4 Mar 30 2012 17:26:10

%S 2,1,3,1,1,4,2,1,1,2,1,2,2,1,2,1,1,3,1,1,3,2,1,1,2,1,2,2,1,1,2,1,3,1,

%T 1,2,1,1,1,2,1,2,2,1,3,2,1,2,1,1,1,1,1,1,2,1,2,1,1,3,2,1,1,1,1,3,2,1,

%U 1,2,1,1,2,1,5,1,1,2,1,1,2,2,1,1,1,1,2,2,1,2,2,1,1,1,1,1,2,1,1,1

%N Number of primes in arithmetic progression starting with 17 and with d=2n.

%C Arithmetic progression is stopped when next term is not prime. E.g. for n=6 (d=12), a=4, that is 17,29,41,53 are prime, while next term, 65, is not prime.

%t bb={}; Do[s=1; Do[If[PrimeQ[17+k*d], s=s+1, bb={bb, s}; Break[]], {k, 10}], {d, 2, 200, 2}]; Flatten[bb]

%Y Cf. A088420, A088421, A088422, A088423, A088424, A088426, A088427, A088428, A088429.

%K easy,nonn

%O 1,1

%A _Zak Seidov_, Sep 29 2003