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A088421
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Number of primes in arithmetic progression starting with 5 and with d=2n.
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9
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2, 1, 5, 2, 1, 5, 2, 1, 4, 1, 1, 3, 2, 1, 1, 2, 1, 2, 2, 1, 5, 1, 1, 5, 1, 1, 4, 2, 1, 1, 2, 1, 3, 2, 1, 1, 2, 1, 2, 1, 1, 4, 1, 1, 1, 2, 1, 5, 2, 1, 2, 2, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 5, 1, 1, 4, 2, 1, 1, 1, 1, 3, 2, 1, 1, 2, 1, 1, 2, 1, 2, 1, 1, 2, 1, 1, 3, 2, 1, 1, 1, 1, 2, 2, 1, 3, 2, 1, 1, 1
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Arithmetic progression is stopped when next term is not prime. E.g. for n=3, a=5, that is 5,11,17,23,29 are prime, while next term, 35, is not prime.
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MATHEMATICA
| bb={}; Do[s=1; Do[If[PrimeQ[5+k*d], s=s+1, bb={bb, s}; Break[]], {k, 10}], {d, 2, 200, 2}]; Flatten[bb]
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CROSSREFS
| Cf. A088420, A088422, A088423, A088424, A088425, A088426, A088427, A088428, A088429.
Sequence in context: A117941 A134566 A128694 * A146024 A146023 A104766
Adjacent sequences: A088418 A088419 A088420 * A088422 A088423 A088424
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KEYWORD
| easy,nonn
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AUTHOR
| Zak Seidov (zakseidov(AT)yahoo.com), Sep 29 2003
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