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Search: id:A130286
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| A130286 |
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Strongly-single primes: primes p such that neither previousprime(p) nor nextprime(p) is a twin prime. |
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+0
1
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| 83, 89, 127, 163, 167, 257, 331, 359, 367, 373, 379, 383, 389, 397, 401, 443, 449, 479, 487, 491, 499, 503, 547, 557, 587, 677, 683, 691, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 769, 773, 787, 907, 911, 919, 929, 937, 941, 947, 953, 967, 971, 977
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Cf. A007510 Single (or isolated or non-twin) primes. See also A000040 The prime numbers, A001097 Twin primes, A071904 Odd composite numbers.
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MATHEMATICA
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PrimeNext[n_]:=Module[{k}, k=n+1; While[ !PrimeQ[k], k++ ]; k]; PrimePrev[n_]:=Module[{k}, k=n-1; While[ !PrimeQ[k], k-- ]; k]; lst={}; Do[p=Prime[n]; If[ !PrimeQ[p-2]&&!PrimeQ[PrimePrev[p]-2]&&!PrimeQ[p+2]&&!PrimeQ[PrimeNext[p]+2], AppendTo[lst, p]], {n, 6!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Jul 21 2009]
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CROSSREFS
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Cf. A000040, A001097, A007510, A071904.
Sequence in context: A106418 A031961 A108751 this_sequence A062677 A045714 A090156
Adjacent sequences: A130283 A130284 A130285 this_sequence A130287 A130288 A130289
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KEYWORD
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nonn
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AUTHOR
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Zak Seidov (zakseidov(AT)yahoo.com), Aug 06 2007
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EXTENSIONS
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Added mathematica, edited some terms Vladimir Orlovsky (4vladimir(AT)gmail.com), Jul 21 2009
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