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A117244
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Single (or isolated or non-twin) primes (A007510) which are not Chen primes (A109611).
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0
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79, 97, 163, 173, 223, 277, 331, 367, 373, 383, 397, 439, 457, 547, 593, 607, 613, 673, 691, 709, 727, 733, 739, 757, 773, 853, 907, 929, 967, 997, 1013, 1069, 1087, 1103, 1123, 1129, 1171, 1181, 1213, 1223, 1237, 1249, 1307, 1373, 1423, 1433, 1447, 1493
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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EXAMPLE
| 79 is single prime, but not Chen prime.
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MAPLE
| isA001358 := proc(n) numtheory[bigomega](n) = 2 ; end proc: isA109611 := proc(n) if isprime(n) then isprime(n+2) or isA001358(n+2) ; else false; end if; end proc: isA007510 := proc(n) if isprime(n) then not isprime(n-2) and not isprime(n+2) ; else false; end if ; end proc: isA117244 := proc(n) isA007510(n) and not isA109611(n) ; end proc: for n from 1 to 4000 do if isA117244(n) then printf("%d, ", n) ; fi; end do ; [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Dec 09 2009]
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CROSSREFS
| Cf. A007510, A109611.
Sequence in context: A015984 A039544 A091819 * A039436 A043259 A044039
Adjacent sequences: A117241 A117242 A117243 * A117245 A117246 A117247
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KEYWORD
| nonn
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AUTHOR
| Jani Melik (jani_melik(AT)hotmail.com), Apr 22 2006
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EXTENSIONS
| Terms beyond 397 from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Dec 09 2009
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