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 A139689 If (n-th Chen prime) + 2 is a prime then 1 else 0. 3
 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(n) = A010051(A139690(n)) = 1 - A064911(A139690(n)). LINKS R. Zumkeller, Table of n, a(n) for n = 1..1000 Eric Weisstein's World of Mathematics, Chen Prime FORMULA a(n) = 2 - A001222(A139690(n)). CROSSREFS Sequence in context: A327861 A131929 A100821 * A204175 A285255 A324823 Adjacent sequences:  A139686 A139687 A139688 * A139690 A139691 A139692 KEYWORD nonn AUTHOR Reinhard Zumkeller, Apr 29 2008 STATUS approved

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Last modified October 15 04:33 EDT 2019. Contains 328026 sequences. (Running on oeis4.)