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A124077
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Indices of the primes in A072762; b(i=a(n)) is prime, b(i) coded as binary word of length=i with k-th bit set iff k is prime (1<=k<=i).
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1
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OFFSET
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1,1
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COMMENTS
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A072762(4211) tested as PRP, others certified primes
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LINKS
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Table of n, a(n) for n=1..7.
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EXAMPLE
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a(3)=7 as A072762(7)=53 and 53 is prime! Also, the binary concatenation of the first a(n) terms of A010051 is prime. E.g. the first 7 term concatenation is binary 0110101 = decimal 53 and is prime!
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MATHEMATICA
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F[j_] := PrimeQ[Numerator[ Sum[ 1/2^Prime[k], {k, 1, j} ] ]] ; Prime[Select[Range[600], F]]
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CROSSREFS
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Cf. A072762, A010051.
Sequence in context: A098860 A106920 A060273 * A006378 A162714 A002396
Adjacent sequences: A124074 A124075 A124076 * A124078 A124079 A124080
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KEYWORD
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hard,nonn
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AUTHOR
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Anton Vrba (antonvrba(AT)yahoo.com), Nov 24 2006
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STATUS
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approved
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