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 A059452 Safe primes (A005385) which are not Sophie Germain primes. 23
 7, 47, 59, 107, 167, 227, 263, 347, 383, 467, 479, 503, 563, 587, 839, 863, 887, 983, 1187, 1283, 1307, 1319, 1367, 1487, 1523, 1619, 1823, 1907, 2027, 2099, 2207, 2447, 2579, 2879, 2999, 3119, 3167, 3203, 3467, 3947, 4007, 4079, 4127, 4139, 4259, 4283 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS A156659(a(n))*(1-A156660(a(n))) = 1. - Reinhard Zumkeller, Feb 18 2009 LINKS C. K. Caldwell, Cunningham Chain W. Roonguthai, Yves Gallot's Proth.exe and Cunningham Chains EXAMPLE 347 is here because 173 is a prime but 695 is not. Except for 7, these primes are congruent to 11 modulo 12. Terminal primes in complete Cunningham chains of first kind, i.e., the chains cannot be continued from these primes. MATHEMATICA lst={}; Do[p=Prime[n]; If[PrimeQ[(p-1)/2], If[ !PrimeQ[2*p+1], AppendTo[lst, p]]], {n, 6!}]; lst (* Vladimir Joseph Stephan Orlovsky, Jun 24 2009 *) CROSSREFS Cf. A005384, A005385, A053176, A059452-A059456, A007700, A005602, A023272, A023302, A023330. Sequence in context: A263920 A124837 A122731 * A245229 A141882 A240569 Adjacent sequences:  A059449 A059450 A059451 * A059453 A059454 A059455 KEYWORD nonn AUTHOR Labos Elemer, Feb 02 2001 EXTENSIONS Broken link updated by R. J. Mathar, Apr 12 2010 STATUS approved

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