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A209618
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Primes separated from their adjacent next primes by a composite number of successive composites.
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2
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139, 181, 241, 283, 337, 409, 421, 547, 577, 631, 691, 709, 787, 811, 829, 919, 1021, 1039, 1051, 1129, 1153, 1171, 1249, 1327, 1399, 1471, 1627, 1699, 1723, 1801, 1831, 1879, 1933, 1951, 2017, 2029, 2053, 2089, 2113, 2143, 2221, 2251, 2311, 2477, 2521, 2557
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OFFSET
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1,1
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COMMENTS
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a(1) = 139 is the first prime separated from the next prime (149) by a composite number (9) of successive composites, namely, 140, 141, 142, 143, 144, 145, 146, 147, 148.
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LINKS
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Table of n, a(n) for n=1..46.
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MATHEMATICA
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ps = Prime[Range[500]]; pos = Position[Differences[ps] - 1, _?(# > 1 && ! PrimeQ[#] &)]; ps[[Flatten[pos]]] (* T. D. Noe, Mar 21 2012 *)
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CROSSREFS
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Cf. A209619.
Sequence in context: A020357 A050967 A071382 * A031928 A095649 A142524
Adjacent sequences: A209615 A209616 A209617 * A209619 A209620 A209621
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KEYWORD
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nonn
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AUTHOR
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Lekraj Beedassy, Mar 21 2012
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STATUS
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approved
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